Clean Energy Production Research Articles

ZnSnS Nanoparticles Synthesized by Simple SMI Technique for Photocatalytic Application

Photocatalysis, driven by semiconductor nanoparticles under visible or ultraviolet light, has emerged as a powerful and sustainable approach for environmental remediation and clean energy production. In this study, we investigate the photocatalytic potential of tin (0, 2, 4, 6, 8, 10) mole % alloyed with zinc sulfide (ZnSnS) nanoparticles as efficient catalysts for various environment and energy-related applications. ZnSnS nanoparticles were produced via a simple microwave irradiation technique. Comprehensive structural characterization through X-ray diffraction (XRD), FESEM, EDAX and HRTEM confirmed the successful incorporation of tin atoms into the ZnS crystal lattice. Optical study indicated significant blue shifts in the absorption edge, extending the light absorption into the visible region, a key advantage for photocatalytic applications. Photocatalytic experiments were conducted to evaluate the performance of Zn-alloyed SnS nanoparticles in degrading organic pollutants and hydrogen evolution from water splitting reactions. Our results revealed remarkable enhancements in photocatalytic activity. The enhanced efficiency can be credited to the creation of fresh energy levels within the bandgap, aiding in the separation and movement of charges, and also to the heightened light absorption caused by the reduced bandgap. Furthermore, stability tests indicated the durability of (ZnSnS) nanoparticles, making them suitable candidates for long-term applications in real-world environments. The observed photocatalytic activity enhancements hold promise for addressing environmental issues, including wastewater treatment, air purification, and hydrogen production for clean energy.

Coal to Clean: Comparing Advanced Electrodes for Desulfurization and Copper Recovery

This study explores the electrochemical desulfurization of coal and the recovery of copper (Cu) using dimensionally stable anode (DSA) electrodes. Background: The research addresses the need for effective sulfur removal from coal to reduce emissions. Methods: Electrochemical desulfurization was conducted using DSA and graphite electrodes, evaluating parameters like activation energy, desulfurization rate, and energy consumption. Cyclic voltammetry and linear sweep voltammetry were used to study the electrochemical properties. Results: The DSA electrode demonstrated superior performance with higher desulfurization rates, lower activation energy, and better response to temperature increases compared to the graphite electrode. Optimal desulfurization was achieved at 50 °C with the DSA electrode, balancing efficiency and energy consumption. Copper recovery from the solution post-desulfurization was effective, with an 86.34% recovery rate at −0.15 V vs. (Ag|AgCl). The energy consumption for the Cu recovery was calculated to be 10.56 J, and the total cost for recovering 1 ton of Cu was approximately 781.20 €. Conclusions: The study highlights the advantages of DSA electrodes for efficient sulfur removal and metal recovery, promoting cleaner energy production and environmental sustainability. Future research should focus on optimizing electrochemical conditions and scaling up the process for industrial applications.

Controlled synthesis of NiCoS@Fe6(OH)12(CO3) as efficient electrocatalyst for oxidation reaction in seawater and urea

In today's world, the efficient preparation of clean energy has become a problem for every country. Hydrogen is a very clean and easy to prepare energy source. In this paper, a hybrid materials of (Fe6(OH)12(CO3)) and sulphide (Ni9S8/Co9S8) was demonstrated as a catalytic electrode for efficient oxidation reaction in seawater and urea. The catalysts were prepared by a three-step hydrothermal-sulfuration-hydrothermal reaction, and the layered composites of hydroxides and sulfides were co-grown into nano-arrays, which exposed more reaction centers and shortened the electron transfer path. The three metal cations were also able to demonstrate different corrosion resistance and excellent adsorption properties for different environments, allowing the catalyst to present better electrochemical activity in seawater as well as in urea solution. In the oxidation reaction in urea solution (1 M KOH+0.5 M urea), the required voltage was only 1.33 V at a current intensity of 50 mA/cm2, and in the water oxidation reaction in seawater, the required voltage was only 1.47 V at a current intensity of 50 mA/cm2 for Ni9S8@Co9S8@Fe6(OH)12(CO3). Unfortunately, the durability of the catalyst need to be improved, the current density dropped from 40 mA/cm2 to 35 mA/cm2 and then remained for 12 h. Meanwhile, the comparison of electrochemical performance tests was performed before and after the IT test, it can be clearly seen that the overall performance of Ni9S8@Co9S8@Fe6(OH)12(CO3) decreased after the stability test, which may be related to the shedding of active species from the surface of the catalyst. As you can see through density functional theory (DFT) that Ni9S8 can promote the adsorption energy of urea and Co9S8 lowers the barrier to electron conduction. Many conjectures were made and confirmed in this study, and finally, it is hoped that seawater as well as industrial wastewater can be better utilized for the production of clean energy.

Exploring the impact of nanoshaped ceria in the methanol decomposition reaction pathway for clean energy production

The effect of facet exposure in ceria nanostructures on the catalytic properties of Pd/CeO₂ during methanol decomposition was investigated. The results showed the structure sensitive nature of this reaction, with the catalytic activity depending on the facet exposed in the ceria nanostructures. Operando DRIFTS-MS and DFT calculations demonstrated that methanol decomposition proceeds mainly via two reaction pathways depending on the exposed nanofacets: the formate and the formaldehyde pathways. The formaldehyde pathway is inhibited on the (111) nanofacets, where only the formate pathway is energetically favoured, in contrast to the (100) and (110) facets. Superior specific catalytic activity was observed in the catalyst with octahedral morphology, attributed to the higher number of oxygen vacancies per unit surface area, which facilitates the decomposition of formates. By gaining a better understanding of the relationship between the shape control of the catalyst, this work contributes to the collective effort of discovering and implementing sustainable low-carbon energy solutions.

Promoting Electricity Production and Cr (VI) Removal Using a Light–Rutile–Biochar Cathode for Microbial Fuel Cells

Microbial fuel cell (MFC) technology holds significant promise for the production of clean energy and treatment of pollutants. Nevertheless, challenges such as low power generation efficiency and the high cost of electrode materials have impeded its widespread adoption. The porous microstructure of biochar and the exceptional photocatalytic properties of rutile endow it with promising catalytic potential. In this investigation, we synthesized a novel Rutile–Biochar (Rut-Bio) composite material using biochar as a carrier and natural rutile, and explored its effectiveness as a cathode catalyst to enhance the power generation efficiency of MFCs, as well as its application in remediating heavy metal pollution. Furthermore, the impact of visible light conditions on its performance enhancement was explored. The X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) analysis validated the successful fabrication of rutile composites loaded with biochar. The maximum current density and power density achieved by the MFCs were 153.9 mA/m2 and 10.44 mW/m2, respectively, representing a substantial increase of 113.5% and 225% compared to the control group. In addition, biochar-supported rutile MFCs showed excellent degradation performance of heavy metal pollutants under light conditions. Within 7 h, the Cr6+ degradation rate reached 95%. In contrast to the blank control group, the removal efficiency of pollutants exhibited increases of 630.8%. The cyclic degradation experiments also showcased the remarkable stability of the system over multiple cycles. This study successfully integrated natural rutile and biochar to fabricate highly efficient cathode photocatalyst composites, which not only enhanced the power generation performance of MFCs but also presented an environmentally sustainable and economically viable method for addressing heavy metal pollution.

Enhancing geothermal efficiency: Experimental evaluation of a high-temperature preformed particle gel for controlling preferential fluid flow

Enhanced Geothermal System (EGS) reservoirs represent a vital frontier in clean energy production. However, short-circulation flow within these reservoirs can significantly affect their immediate efficiency and long-term viability. Injected cold fluids moving through wide fractures or direct channels between injection and production wells reduce thermal production temperatures, disrupting energy output. Preformed Particle Gels (PPGs) have proven effective in controlling preferential fluid flow in oil and gas reservoirs, effectively regulating fluid movement. This work explores the potential of a novel High-Temperature Preformed Particle Gel (HT-PPG), designed for geothermal applications, to plug fractures in a simulated geothermal reservoir. Core flooding experiments in coated and uncoated sandstone models were conducted under varying HT-PPG sizes, swelling ratios, and fracture widths to determine gel plugging efficiency. Variations in the HT-PPG injection pressure, breakthrough pressure, and residual resistance factor (Frr) were evaluated. Water breakthrough pressures can reach 464.10 psi/ft. While the stable injection pressure of HT-PPG decreased with increasing swelling ratio and fracture width, it was higher in uncoated cores. The HT-PPG significantly sealed the fractures, drastically reducing conductivities to millidarcy levels. This work validates HT-PPG a robust solution to mitigate fluid diversion challenges in sandstone EGS reservoirs, enhancing performance and advancing sustainable geothermal energy production.

Clustered VCoCOx Nanosheets Anchored on MXene–Ti3C2@NF as a Superior Bifunctional Electrocatalyst for Alkaline Water Splitting

Ti3C2, one typical MXene, has great potential to be coupled with various transition metals. Herein, a novel and effective catalyst is developed by synergistically loading VCoCOx onto Ti3C2‐modified nickel foam (VCoCOx–Ti3C2@NF). Field emission scanning electron microscope and high‐resolution transmission electron microscopy are employed to characterize the morphology and structure. As expected, the catalyst optimized by response surface methodology attains overpotentials of 290 and 64 mV and Tafel slopes of 82 and 79 mV dec−1 for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), respectively. By using the bifunctional VCoCOx–Ti3C2@NF catalyst, the water splitting current density achieves 10 mA cm−2 in 1.0 mol L−1 KOH electrolyte at cell voltage of 1.52 V, comparable with the noble metal electrolyzer Pt@C@NF||RuO2@NF (1.57 V). Furthermore, the resulting catalyst exhibits excellent cycling durability after 120 h of continuous catalysis, which retains 103.8% and 105.4% of potential (V vs reversible hydrogen electrode) for OER and HER, respectively. Density functional theory calculation reveals that the Gibbs free energy barriers for the OER and HER intermediates are reduced due to the integration of VCoCOx with Ti3C2@NF. The fabricated VCoCOx–Ti3C2@NF catalyst is a promising electrochemical material for clean energy production.

Investigation of low carbon emission and high thermal efficiency of diesel engine combined with high-pressure direct injection of hydrogen carrier: Ammonia

Ammonia, as a zero-carbon fuel, has the potential to serve as a medium for the production, transportation, and utilization of clean energy. The scaling up of green ammonia production also necessitates broader utilization channels for ammonia. Applying ammonia as a fuel in engines is an effective way to reduce carbon emissions. This paper employs dual direct injection technology of ammonia and diesel in a novel ammonia-fueled engine to implement various control strategies and investigates their effects on combustion and emission performance. The results indicate that when the ammonia injection timing is advanced from −40°CA ATDC to −60°CA ATDC, the flash boiling of liquid ammonia decreases the indicated thermal efficiency (ITE) below 39% and increases unburned gas emissions. Globally, injecting ammonia during the intake stroke could receive better performance. Split injection strategies of diesel significantly improve the ITE, especially under a higher pilot-injection ratio of 75%. Additionally, increasing the load benefits the ammonia combustion process. Raising the IMEP to 12 bar improves ammonia combustion efficiency to over 95%, with an ITE reaching 49%.

Synergies quantification and evolution on air pollutant and CO2 emissions driven by different socio-economic effects

Realizing a synergistic reduction of air pollutant and CO2 emissions (APCE) is an important approach to promote a green socio-economic transformation in China, and it can provide a solid foundation for the achievement of clean energy production and climate action under a sustainable development goal framework. The objective of this study is to explore the quantitative relationship and evolution of synergies between APCE in industrial sectors driven by different socio-economic effects from 2007 to 2020 in China. The results indicated that the main sectors of pollutant emissions had consistency, however, large differences in the reduction efficiency of emissions exist among pollutants. The efficiency in reducing CO2 emissions was about 48% lower when compared with reductions of SO2 (95%), NOx (86%), and smoke and dust (83%) emissions from 2007 to 2020. The effects of improved technology were the main contributor to a reduction in pollutant emissions, but the synergies between APCE driving by it were not achieved. While the synergies between APCE driven by structure and final demand effects were significant. The synergies between NOx and CO2 emissions were stronger driven by final demand structure and type effects, with correlation coefficients of 1.06 and 1.13, respectively. Besides, the degree of synergistic reduction between APCE in most industrial sectors was around zero. Therefore, the efficiency of synergistic pollution reduction should be improved with the development of a synergistic governance system for industrial sectors. The structural decomposition analysis based on input-output model combined with the cross-elasticity analysis method to quantitively synergies between APCE from the consumption (demand) perspective, considering the connections between industrial sectors with socio-economic developing, which would contribute to the industrial synergistic reduction and green transformation as the consumption driven gradually increasing.

Ferroelectric/Piezoelectric Materials in Energy Harvesting: Physical Properties and Current Status of Applications

The inevitable feedback between the environmental and energy crisis within the next decades can probably trigger and/or promote a global imbalance in both financial and public health terms. To handle this difficult situation, in the last decades, many different classes of materials have been recruited to assist in the management, production, and storage of so-called clean energy. Probably, ferromagnets, superconductors and ferroelectric/piezoelectric materials stand at the frontline of applications that relate to clean energy. For instance, ferromagnets are usually employed in wind turbines, superconductors are commonly used in storage facilities and ferroelectric/piezoelectric materials are employed for the harvesting of stray energy from the ambient environment. In this work, we focus on the wide family of ferroelectric/piezoelectric materials, reviewing their physical properties in close connection to their application in the field of clean energy. Among other compounds, we focus on the archetypal compound Pb(Zr,Ti)O3 (or PZT), which is well studied and thus preferred for its reliable performance in applications. Also, we pay special attention to the advanced ferroelectric relaxor compound (1−x)Pb(Mg1/3Nb2/3)O3−xPbTiO3 (or PMN-xPT) due to its superior performance. The inhomogeneous composition that many kinds of such materials exhibit at the so-called morphotropic phase boundary is reviewed in connection to possible advantages that it may bring when applications are considered.

Illuminating the path to decarbonization: Nuclear energy consumption, clean energy production, and sustainable fuel production for long-term development

The global concern over carbon emissions has necessitated a deep understanding of energy use and air pollution. The fossil fuel- and nuclear-dependent Russian economy is an exciting exception. It examined how nuclear energy consumption (NEC), electricity generation, R&D investment, clean energy production technology, e-commerce penetration, capital creation, and carbon pollution affect the Russian economy. Short- and long-term interactions between these variables are assessed using the ARDL-Bound testing model for 1995Q1–2020Q4. The results show that NEC negatively correlates with CO2 emissions. The study also supports the inverted U-shaped Environmental Kuznets Curve (EKC) hypothesis, showing a positive and significant relationship between clean power production technology and CO2 emissions and a negative and significant relationship between square clean alternative energy innovation and CO2 emissions. Scientific and technical expenditures, fossil fuel coal liquefaction, and investment all negatively and statistically significantly affect CO2 emissions. However, the analysis implies that e-commerce increases CO2 emissions. These findings highlight the need for significant R&D investment to create precise and realistic ways to decrease carbon emissions and protect the environment in accordance with COP 26 targets. These findings have significant implications for the Russian economy, showing that improving energy sources and investing more in R&D may reduce carbon emissions.

Effective hydrogen production and coupling degradation of organics (4-nitrophenol, methylene blue, and Rhodamine B) in wastewater by electrospun PAN@Fe0 composite nanofibers

The pursuit of clean energy generation and environmental preservation is of utmost importance for societal progress. However, couple clean energy production and pollution control is still a difficulty. In this study, a novel electrospun composite mat, with nano zero valent iron (Fe0, nZVI) encapsulated into polyacrylonitrile (PAN) nanofibers was acted as a catalyst. The activation energy (Ea) for the hydrolysis of NaBH4 to produce hydrogen is 22 kJ·mol−1, hydrogen atom utilization efficiency (HGE) of NaBH4 is 60.80%. Three kinds of organic dyes 4-nitrophenol (4-NP), methylene blue (MB), and Rhodamine B (RhB) were served as the model pollutant, to construct NaBH4-organic system for energy production and pollution reduction. The NaBH4-organic system demonstrates a collaborative capability to simultaneously remove organic pollutants and generate hydrogen, with a coupling equilibrium point between the two processes. The hydrogen generation rate (HGR) and HGE increased with the concentration of pollutants increased. The degradation of 4-NP, MB, and RhB followed pseudo-first-order kinetics, with RhB degrading dosage 20 and 44 times higher than 4-NP and MB, respectively. H2 and H· contributed to the organic degradation. nZVI directly participated in the formation H2 and H·. PAN@Fe0 possessed good recyclability and moderate cost. The degradation process adhered to the classical surface reaction controlled Langmuir-Hinshelwood (L-H) model. The integration of synergistic production capacity and pollutant degradation aligns well with the principles of green chemistry and sustainable development. This study demonstrates a novel approach to no precursor loss catalysts preparation, efficient production clean H2, advanced treatment of dye-containing wastewater, carbon neutral operation of sewage treatment plant.

Renewable energy, regional tourism, and exports to tackle stagnant growth in developed economies

This study examines the effects of energy resources in the form of clean and unclean energy on the economic progress of 30 selected developed economies. This study used data from 1990 to 2020 and it employs the CS-ARDL method to obtain results. The results present that both clean and unclean energy significantly stimulate economic progress. The findings further expose that foreign investment resources in the form of inflow are significant factors that accelerate economic progress in developed economies. The results reveal that tourism development, capital accumulation, and exports are significant factors in boosting economic progress in the selected economies. Estimates from Dumitrescu and Hurlin's method for heterogeneous panels confirm the presence of the feedback-effect hypothesis for unclean energy, while the energy-conservation hypothesis holds for clean energy. This study suggests that targeting low-cost clean energy production is crucial for promoting economic growth and protecting the environment through carbon mitigation strategies. There is also a need to develop a policy framework that emphasizes the transformation of industry towards clean energy at a macro level. Furthermore, transitioning from unclean to clean energy may enhance economic progress by improving environmental quality norms in the selected developed economies. Finally, policies for tourism development, export improvement, and increased inflow of FDI should be directed towards fostering clean energy agreements and achieving environment-friendly economic progress in developed economies.

Local potentials for achieving sustainable development goals: qualitative evidence from local governments in Türkiye

ABSTRACT Although academia occasionally emphasises prioritising the local dimension in achieving the Sustainable Development Goals (SDGs), the potential of local governments to contribute to SDGs accomplishment remains a relatively unexplored area within academic discourse. This study aims to elucidate the potential of local governments in achieving the SDGs with qualitative evidence from Türkiye, conducting content analysis on strategic targets presented in a total of 382 strategic plans from 331 municipalities and 51 Special Provincial Administrations (SPAs) covering the years 2020–2024. Notable findings indicate a robust commitment from both local government types to SDG11, emphasising social and cultural life, urban environment, and liveability- a shared intent to enhance resident well-being. However, a substantial gender equality (SDG5) gap persists in both types, while SDGs (7, 12, 13, 14, 17) centred on clean energy, climate change, and sustainable production patterns reveal a weak mutual strategic orientation.

Improving the energy efficiency of carbon capture process: The thermodynamic insight

The efficient use of energy is an important challenge in engineering tasks. Even with the end-of-pipe treatment method, the carbon capture process has possibilities to improve its efficiency with heat integration. Since exergy analysis helps detect the most efficient way of energy intensification, exergy investigation based on thermodynamic analysis is carried out to improve energy efficiency. Two cases for exergy destruction calculation can be considered and compared depending on the operation of the capture process: (i) the stand-alone situation, where utilities are applied, and (ii) the total site integration, where sources and sinks are available at every temperature level of the carbon capture process. Besides heat integration, the application of oxyfuel technology can further improve thermodynamic efficiencies reducing the detrimental exergy destruction. Air-combustion exhibits higher exergy destruction compared to oxyfuel-combustion, particularly at high carbon dioxide removal efficiency levels. Heat-integrated configurations nearly double thermodynamic efficiency, especially in the cases of oxyfuel technologies. Therefore, it is recommended that, for the sake of cleaner energy production, both oxyfuel technologies and heat integration should be applied to enhance carbon capture process’ energy efficiency.

Kinetic analysis of solid fuel combustion in chemical looping for clean energy conversion

Chemical looping combustion (CLC) offers an advanced, eco-friendly method for converting solid fuels into energy with inherent CO2 capture, presenting a cost-efficient solution. The kinetics of solid fuel CLC, crucial for reactor design, are not well-understood, limiting its application and optimisation. Conducting a comprehensive kinetic analysis of solid fuel CLC is crucial, as it examines the combustion of both volatiles and fixed carbon, thereby addressing existing knowledge gaps and advancing clean conversion of solid fuels. In this study, a comprehensive kinetic analysis method for the first time has been applied to investigate the kinetics of CLC of low-volatile semi-anthracite coal with CuO at temperatures of 700–950 °C under varied oxygen excess ratios (0.5, 1.0, and 2.0). The results show that the combustion of coal in CLC can be divided into three distinct stages. The combustion of coal with CuO initiates with the combustion of volatiles interacting with solid CuO at 450–580 °C, where the combustion efficiency varies between 3–6 wt%. This is followed by a complex simultaneous mechanism involving gas-phase volatiles and solid-phase CuO, as well as gas-phase oxygen and solid-phase fixed carbon under non-isothermal conditions. The combustion efficiency is ranged 19–71 wt% at the temperature ranges from 580 °C to the isothermal temperatures of 750–950 °C. The activation energy for the combustion of volatiles was determined as Ea = 119 kJ/mol, whereas the initial combustion of fixed carbon in the non-isothermal stage ranged between Ea = 39–53 kJ/mol. The rate of combustion is initially limited by the oxygen diffusion rate from CuO, but with additional oxygen carriers and increased temperature, the reaction becomes constrained by first-order kinetics. Upon reaching the isothermal stage, the final combustion phase between fixed carbon and gas phase oxygen occurs, and the combustion efficiency increases to 77–96 wt% at 750–950 °C. The activation energy for fixed carbon combustion under the isotherm stage was approximately Ea = 234 kJ/mol, with a reaction rate constant (k0) of 7.84 × 109 min−1. This pioneering study not only clarifies the multi-stage kinetics of solid fuel CLC, bridging significant gaps in current knowledge but also sets the foundation for the enhanced design and efficiency of CLC systems for cleaner energy production.

Elevating Oxygen Evolution using Iron Phthalocyanine Infused Vanillic acid Electrocatalyst.

Oxygen evolution reaction (OER) is the bottle neck step in water splitting reaction towards the realization of hydrogen based clean energy production and storage. Metal air batteries and polymer electrolyte membrane fuel cells (PEMFC) are the alternative green energy systems that utilise O2 and H2 in the production of continuous and high energy output without the utilization of carbon based fuels which are the major sources of pollution. Transition metal based N4 organics are explored extensively as oxygen electrocatalysts i. e., OER and oxygen reduction reaction (ORR) catalysts because of their ease of synthesis, tuneable properties, low cost and high performance with long term stability. Here, vanillic acid functionalized iron phthalocyanine (FeVAPc) was synthesised and characterised by various spectroscopic techniques. The novel FeVAPc exhibited good thermal stability and was coated on Ni foam for OER studies. The scanning electron microscopy images showed net-work like surface morphology and the X-ray photoelectron spectroscopy indicated the presence of Fe in +3 oxidation state. The Ni/FeVAPc demonstrated excellent electrocatalytic activity for OER with overpotential of 312 mV at 10 mA.cm-2 current density in 1.0 M KOH electrolyte. The designed organic based catalyst exhibited lesser Tafel slope value which is nearer to the benchmark catalyst, IrO2. The proposed catalyst exhibited good stability as phthalocyanines are highly stable and do not undergo decomposition even in strong acidic and basic corrosive media. Integration of FeVAPc onto the Ni foam resulted in higher mass activity, lower charge transfer resistance, high active surface area leading to enhanced conductivity and activity. The fabricated Ni/FeVAPc is an appropriate cost-effective, efficient and stable catalyst for OER towards industrial applications.

Green synthesis of Mn3O4@CoO nanocomposites using Rosmarinus officinalis L. extract for enhanced photocatalytic hydrogen production and CO2 conversion

In response to the urgent need for sustainable environmental remediation technologies and clean energy production, this study introduces an eco-friendly synthesized Mn3O4@CoO nanocomposite (MCNC) leveraging the natural reducing capabilities of Rosmarinus officinalis leaves (L.) extract. Focused on the hydrogen evolution reaction (HER) and CO2 methanation, our findings reveal significant enhancements in photocatalytic activity and CO2 methanation efficiency. The MCNC exhibited a promising hydrogen production rate of up to 823 μmol g−1 h−1 and a CO2 conversion efficiency exceeding 84 % under optimal conditions. The investigation highlights the synergistic interfacial effect between Mn3O4 and CoO, contributing to notable performance improvements. Additionally, the study explores the role of catalyst quantity in optimizing reaction efficiencies, presenting a scalable and environmentally benign approach to address global energy and environmental challenges. The apparent quantum efficiency (AQE%) was calculated to be 1.92, 2.39, 2.73, 3.21, 3.44, and 3.56 % for mass values of 15, 25, 35, 45, 55, and 65 mg, respectively. Furthermore, the CO2 methanation also shows a rise with the increase in catalyst quantity. A mass of 0.35 mg achieved a remarkable CO2 conversion efficiency of 71.9 %, while its 0.5 mg counterpart showcased an even more striking CO2 conversion efficiency of 84.4 %. The green synthesis method, characterized by its low energy requirement and the absence of toxic chemicals, aligns with the sustainable practices sought in environmental chemistry and nanotechnology. This work not only opens new avenues for developing efficient photocatalysts but also contributes to the broader application of green synthesized nanomaterials in environmental remediation and clean energy generation.

Integrated doped-Ru electrocatalyst with excellent H adsorption–desorption and active site on hollow tubular structures for boosting efficient hydrogen evolution

Electrochemical water splitting for hydrogen production is an ideal process for clean energy production. However, highly active and low-cost electrocatalysts are essential and challenging. In this work, a multi-component Cu-based catalyst (Ru-M-C-Cu), synergized with ruthenium (Ru) heteroatom doping, was synthesized via a facile immersion-calcination-immersion method. Based on the cotton biomass substrate, a hollow tubular structure was obtained. By virtue of its distinctive structure and high carbon content, cotton biomass assumed a dual role as a sacrificial template and a reducing agent in the eco-friendly synthesis of electrocatalysts, which was instrumental in the creation of a multi-component system augmented by heteroatom doping. The multi-component system was constructed by in-situ transformation and redox reaction during calcination in an oxygen-free environment. The Ru-M-C-Cu catalyst exhibited a competitive overpotential of 108 mV at a current density of 10 mA cm−2 for alkaline hydrogen evolution reaction (HER). The satisfactory catalytic performance of Ru-M-C-Cu can be attributed to the fact that the Ru-O-Cu catalytic centers enhanced the adsorption and desorption abilities of the Cu–O active sites toward hydrogen. Furthermore, the hollow tubular structure allowed the electrolyte to make full contact with the active sites of the Ru-M-C-Cu catalyst, thus accelerated the HER kinetics. The catalyst showed structural and chemical stability after a 12-hour successive test. Besides, the production cost of Ru-M-C-Cu was significantly reduced by 99.1 % than that of commercial 20 % Pt/C, showing the potential as an alternative catalyst by offering a more accessible and sustainable source. This work provides a new design of sustainable low-budget electrocatalysts with the proposed strategies expected for producing clean and renewable hydrogen energy.

Polychloride and benzene ring synergistically boosting photocatalytic degradation and nitrogen fixation performances of carbon nitride

The limited active site exposure, insufficient light absorption and poor charge behavior of carbon nitride (CN) limit its application in environmental remediation and clean energy production. In this study, ultrathin porous CN with enhanced photocatalytic activity was constructed by doping 2,2′,5,5′-Tetrachlorobenzidine (TB) into CN framework. The synergistic effect of polychloride and benzene rings on CN leads to the significant enhancement of range/intensity of visible-light harvest and charge behavior, as well as specific surface area. The optimal sample achieves 100% tetracycline photodegradation efficiency with a rate constant approximately 9 times of pristine CN, and total organic carbon removal efficiency reaches 78.2%. Moreover, photocatalytic ammonia production rate is 7 times of pristine CN. Through active species trapping experiments, ESR, LC-MS, toxicity prediction and DFT calculations, the main active species, degradation pathway, intermediates toxicity and enhanced mechanism of photocatalytic activity are investigated. This work provides a reference for simultaneously regulating the morphology, light absorption and charge behavior of CN-based photocatalyst for addressing environmental and energy concerns.