Sustainable Technologies Research Articles

The efficacy of nano‐cellulose‐based composites in heavy metal removal from wastewater: a comprehensive review

AbstractThis comprehensive study delves into the innovative application of nano‐cellulose‐based composites for addressing the multifaceted challenges of wastewater treatment. This review introduces the innovative use of nano‐cellulose composites, particularly highlighting the novel synthesis routes that enhance their pollutant adsorption capabilities beyond conventional materials. These materials stand out for their regenerative properties and integration with functionalized matrix materials, marking significant advancements in sustainable wastewater treatment technologies. As the environmental and public health risks associated with untreated wastewater escalate, the development of efficient and sustainable treatment technologies has become crucial. Nano‐cellulose composites, derived from natural and renewable sources, offer significant advantages, including high surface area, superior mechanical strength, and notable biodegradability. This review explores various synthesis methods—mechanical, chemical, and enzymatic—that enhance the adaptability of nano‐cellulose composites to meet specific treatment needs. Main findings demonstrate these composites' effectiveness in removing a wide array of pollutants, including heavy metals, organic compounds, dyes, and microbial contaminants, with detailed removal capacities provided for each pollutant category in comparative tables. The potential for regeneration and reuse highlights their practical sustainability and economic viability. Future research should focus on improving production scalability and cost‐effectiveness, assessing environmental impacts and ensuring regulatory compliance to advance the application of nano‐cellulose composites in wastewater treatment. This study paves the way for these materials to become central to innovative, efficient, and eco‐friendly wastewater management strategies. © 2024 Society of Chemical Industry (SCI).

Seeds of change: A bibliometric study on sustainable technologies and business strategies in agriculture

The transition to sustainable agricultural practices is critical in the face of escalating climate challenges. Despite significant advances, the integration of green technologies within agribusiness remains underexplored. This study undertakes a comprehensive bibliometric analysis, utilizing data from the Web of Science Core Collection (1990–2023), to elucidate the integration of green technologies within agribusiness strategies. The research highlights key trends, influential authors, prominent journals, and significant thematic clusters, including biogas, biochar, biotech remediation, sustainable agriculture transition, low-carbon agriculture, and green strategies. By employing R, Bibliometrix, and VOSviewer, the study provides a nuanced understanding of the research landscape, emphasizing the critical role of strategic planning, policy frameworks, technological innovation, and interdisciplinary approaches in promoting sustainable agricultural development. The findings underscore the growing scholarly interest in sustainable practices, driven by global initiatives such as the UN’s 2030 Agenda and the Paris Agreement. This study contributes to the literature by offering qualitative insights and policy implications, highlighting the necessity for a holistic integration of green technologies to enhance the environmental and economic viability of agribusinesses.

Interference mechanism of electrolyte cations on vanadium-oxygen binary doped carbon nitride for hydrogen evolution from artificial seawater splitting: Coupling experiments, DFT calculations and machine learning

Photocatalytic H2 production from seawater splitting is a promising method for sustainable energy conversion technology. The vanadium-oxygen binary doped carbon nitride (VOX-CN) is successfully prepared for H2 production. Benefiting from the electronic structure alteration, the maximum H2 yield on VOX-CN in artificial seawater reaches 4475.74 μmol h−1g−1, 10 times higher than that of CN in deionized water. The impact of ions on the photocatalytic activity of VO2-CN is followed by Na+ > Mg2+ > K+ > Ca2+. The adsorption of electrolyte ions promotes the formation of delocalized electron clouds on the surface of VO2-CN, facilitating more electrons to participate in H+ reduction. Screening based on six machine models, the decision tree regression algorithm is used to reveal the interaction between cation type, their concentration and H2 yield. Pearson heatmap indicates that Na+, Mg2+, and K+ ions are positively correlated with H2 yield, whereas Ca2+ shows a negative correlation. The interactions among Na+, Mg2+ and K+ atoms facilitate H2 production in multi-ion system, whereas Ca2+ ions do the opposite, especially for high concentration. This work proposes new insights into the interference on H2 yield between the structure alteration of CN framework and the change of ion type and concentration.

Solid waste management in Ugandan developing cities: Material flow analysis and sustainable practices for reducing the global warming potential.

The introduction of appropriate solid waste management (SWM) strategies can foster the mitigation of waste open dumping and burning in low-income developing cities. In this work, the SWM system in Gulu (Uganda) has been studied, and a material flow analysis, also of informal flows of waste, has been carried out. Moreover, the effectiveness of the SWM system of St. Mary's Lacor Hospital in Gulu was evaluated. Waste has been characterized and a material flow analysis allowed to highlight the difference with the current situation in the remaining part of Gulu. The sustainable practices already implemented in the hospital compound were studied to be replicated in Gulu to mitigate SWM impact in terms of global warming potential. Inadequate financial resources pose a hurdle for Gulu municipality in managing municipal solid waste (MSW) effectively. The SWM system of the hospital demonstrated both financial and managerial competence, paving the way to promote waste recycling actions acting as a hub for fostering sustainable and health-conscious valourization technologies, while discouraging waste open burning and dumping. This study estimated that the total CO2-eq emissions from open dumping and open burning avoided in 2030-2050, if Gulu would appropriately dispose of MSW by 2030, are equal to about 17,000 metric tonnes per year (t year-1). This work suggests appropriate strategies to mitigate waste open burning in low-middle income countries. The results can be helpful for waste management planners and practitioners providing important information for the use of appropriate technologies in low-middle income developing cities.

Z-Scheme Enabled 1D/2D Nanocomposite of ZnO Nanorods and Functionalized g-C3 N4 Nanosheets for Sustainable Degradation of Terephthalic Acid.

The urgent need to mitigate water pollution and achieve Sustainable Development Goal 14 (SDG 14)-Life below water, necessitates developing efficient and eco-friendly wastewater treatment technologies. This research addresses this challenge by photocatalytic degradation of terephthalic acid, a precursor for PET bottles using environment-friendly and biocompatible photocatalysts. The 1D/2D nanocomposite comprising zinc oxide (ZnO) nanorods and functionalized graphitic carbon nitride (Zn-TG) nanosheets were synthesized and thoroughly characterized. The nanocomposite effectively mitigated the individual drawbacks of Zn-TG agglomeration and the wide band gap of ZnO as confirmed through zeta potential and Tauc's plot studies, respectively. The synthesized nanocomposite achieved ~100 % degradation within 60 minutes, exhibiting superior kinetics (~2.5 times) compared to pristine samples. The enhanced degradation efficiency was elucidated by efficient charge carrier transfer (~5 times faster) and separation (~2 times improved) as confirmed through electrochemical impedance spectroscopy and time-resolved photoluminescence studies. The proposed Z-scheme pathway provides mechanistic insights. This proposed mechanism is supported by extensive electron paramagnetic resonance (EPR) and scavenger studies. The liquid chromatography-mass spectrometry (LC-MS) analysis confirms the formation of less toxic byproducts for ensuring that the wastewater treatment process is efficient and environmentally friendly. This research helps in developing a highly effective and sustainable wastewater treatment technology.

Asymmetric Alkyl Chain Engineering for Efficient and Eco-Friendly Organic Photovoltaic Cells.

Recent advancements in organic photovoltaic (OPV) cells have resulted in power conversion efficiencies (PCEs) surpassing 20%. However, the use of halogen solvents in the fabrication of OPV cells raises concerns due to their potential environmental and health impacts. In this work, a novel non-fullerene small molecule acceptor BO-AM-4F, featuring an asymmetric alkyl chain design that includes a 2-butyloctyl and a unique 6-(hexylamino)-6-oxohexyl chain is synthesized. This design significantly improves molecular packing, crystallinity, and electrostatic potential distribution compared to the controlled acceptor DBO-4F, which possesses symmetric 2-butyloctyl chains. When combined with the polymer donor PBDB-TF and processed using the non-halogen solvent o-xylene, the BO-AM-4F-based OPV cell achieves an impressive PCE of 18.0%, surpassing the 16.6% PCE observed in the PBDB-TF:DBO-4F device. Furthermore, the PBDB-TF:BO-AM-4F system demonstrates enhanced photostability and thermal stability compared to its DBO-4F counterpart. These findings emphasize asymmetric alkyl chain engineering as an effective strategy for developing high-performance, environmentally friendly OPV materials. This represents a significant step towards sustainable OPV technology.

A limiting integrative effort plastic waste in the sea of Indonesia and China: The Penta Helix model perspective

Indonesia ranks as the second-largest source of plastic garbage in marine areas, behind China. This is a critical problem that emphasises the need for synergistic endeavors to safeguard the long-term viability of marine ecosystems. The objective of this work is to examine the implementation of the Penta Helix model in the management of marine plastic trash. For this purpose, a Systematic Literature Review (SLR) was carried out, utilizing scholarly papers sourced from the Science Direct, Scopus, and Web of Science databases. The analysis centred on evaluating the Penta Helix model as a cooperative framework for tackling plastic waste management in the marine environments of Indonesia and China. The results suggest that the Penta Helix methodology successfully enables the amalgamation of many interests and resources, making a valuable contribution to the mitigation of plastic pollution in the waters of both nations. In order to advance a more comprehensive and sustainable approach to plastic waste management, this multidisciplinary plan brings together stakeholders from government, academia, business, civil society, and the media. Under this framework, the government is responsible for formulating laws, guidelines, and programs to decrease the use of disposable plastics and improve waste management infrastructure, all while guaranteeing adherence to environmental constraints. Simultaneously, the industrial and academic sectors are responsible for creating sustainable technology and pioneering business strategies, while civil society, in collaboration with the media, has a crucial role in increasing public consciousness regarding the destructive effects of plastic trash. This comprehensive strategy emphasizes the need of synergistic endeavors in tackling the intricate issues of marine plastic contamination.

Investigating novel thin-film nanocomposite membranes for sustainable water recovery using fertilizer-driven forward osmosis – Experimental and machine learning approaches

Water recovery from municipal wastewater can augment freshwater resources to meet increasing demand. An osmotic-driven membrane separation process- forward osmosis (FO) is currently being explored as a sustainable technology. This work proposes to address the challenges associated with FO namely (i) robust membrane and (ii) draw solute (DS) recovery. Robust thin-film nanocomposite membranes incorporating a) nickel ferrite or b) nitrogen-enriched nanoporous polytriazine (NENP-1) covalent organic framework were fabricated with enhanced hydrophilicity, surface roughness and anti-fouling properties. The optimum membranes M2 and C2 displayed a pure water flux of 4.86 ± 0.11 and 5.4 ± 0.2 L/m2h respectively and a specific reverse solute flux (SRSF) <<1 when using 1 M NaCl solution as the DS (feed solution – DI water). Fertilizer-driven FO (FDFO) was proposed as the diluted DS need not be recovered but could be used directly for irrigation. The pure water flux for both M2 and C2 membranes were in the following order for the fertilizers used as DS (1 M) - (NH4)2SO4 + (NH₄)₂HPO₄ > (NH4)2SO4 > (NH₄)₂HPO₄ which indicates that the mixed ions in the DS enhanced the water permeance. In all cases, the SRSF was < 1 g/L indicating the feasibility of the process. The membranes exhibited a TOC removal of > 90 % from synthetic municipal wastewater containing persistent organic pollutants and personal & pharmaceutical care products and the membranes could be regenerated after washing with a 10 mM solution of SDS for 5 cycles of operation. Further, ANN was used to develop a predictive model for water flux in FO membranes and the optimized architecture of 7–5–50–40–1 displayed a remarkable overall R2 value of 0.98 (MSE= 0.027). The FDFO process using the fabricated thin-film nanocomposite membranes holds enormous potential to be investigated in larger-scale studies.

Ten Simple Rules for Incorporating the UN Sustainable Development Goals (SDGs) into Environmental and Natural Science Courses

In 2015, the United Nations (UN) established 17 Sustainable Development Goals (SDGs) to combat poverty, inequality, and climate change. Recently, integrating these goals into higher education curricula has emerged as essential for fostering positive environmental and civic engagement. Challenges persist, particularly the prioritization of social and economic concerns over eco-centered principles and ecopedagogy. Education must emphasize the politics of environmental issues, advocating sustainable practices that benefit both humans and nonhuman species. This article proposes ten simple rules for incorporating the SDGs into undergraduate courses in ecology, evolution, and environmental science. We conducted a literature review, analyzing 940 publications from 2014 to 2024 using ISI Web of Science and Google Scholar. We focused on fields like Green Sustainable Science and Technology and Environmental Education to identify the best practices for integrating SDGs. Our findings link pedagogical successes to the SDGs, facilitating effective educational strategies. For practical sustainability education, students must grasp the interplay between the environment and societal elements such as diversity, justice, and resilience. Connecting course topics to the SDGs offers a powerful framework for teaching undergraduates about complex environmental challenges. Our research highlights a novel approach to embedding SDGs in environmental education, promoting critical thinking and literacy across various settings.

Catalyst Activation of Peroxymonosulfate for Reactive Species Generation and Organic Pollutant Degradation: A Mini Review

This review focuses on the application and mechanisms of peroxymonosulfate (PMS) in advanced oxidation processes (AOPs). It clarifies the significance of PMS in degrading organic pollutants, highlighting its high efficiency in treating persistent contaminants, such as antibiotics. The review details the roles and mechanisms of various catalysts, including single-atom catalysts, metal oxides, non-metal oxides and their composites, as well as metal-organic frameworks (MOFs), in activating PMS. It emphasizes the influence of catalyst surface active sites on both radical and nonradical activation pathways. Key factors affecting PMS activation efficiency, such as PMS concentration, pH value, coexisting ions, and temperature, are examined to underline the importance of optimizing these parameters for effective reaction conditions. By synthesizing existing research, the review not only illustrates the extensive application potential of PMS in AOPs but also identifies future research challenges and directions. This provides a theoretical foundation and technical support for developing efficient, economical, and sustainable water treatment technologies.

Influence of impurities on the use of Fe-based powder as sustainable fuel.

Sustainable energy production, inherently transient and non-uniformly distributed around the world, requires the rapid development of sustainable energy storage technologies. Recently, pure iron powder was proposed as a high-energy density carrier. While promising, challenges are faced, such as nanoparticle emissions, micro-explosions or cavitation. In this work, a screening of the impact of the most common impurities in iron sources on these mechanisms was conducted through purely thermodynamic simulations. Two idealized models were considered to obtain a range of plausible flame temperatures and emitted gases when considering a purely diffusive regime in standard conditions and stoichiometric air-fuel mixture. The flame temperature and iron evaporation are increasing with the specific energy. A strong evaporation of C, S, Mo, Cu and P is also expected. Most impurities are predicted to decrease cavitation, except for Mn and MnO. The regeneration process by hydrogen-based direct reduction in fluidized bed reactors is also discussed. MgO and CaO are the most promising additions in terms of reducing nanoparticles and porosities, as well as to improve the fluidization and reduction kinetics of the combusted products. The potential of Fe powder as sustainable fuel, already very promising, could be further improved by the addition of selectively chosen impurities.This article is part of the discussion meeting issue 'Sustainable metals: science and systems'.

Green technologies for extracting plant waste functional ingredients and new food formulation: A review.

Nowadays, there is a growing interest in food waste recovery by both consumers and companies. Food waste of plant origin is a source of bioactive compounds, such as phenolic acids, anthocyanins, flavonoids, phytosterols, carotenoids, and tocopherols, with well-known antioxidant, anti-glycemic, and antimicrobial properties. The use of green and sustainable technologies to recover bioactive compounds from food waste is a possible solution to valorize waste following the principles of green chemistry. Furthermore, today's consumers are more attracted, informed, and aware of the benefits associated with the consumption of functional foods, and with this in mind, the use of extracts rich in beneficial compounds obtained by green technologies from food waste can be a valid alternative to prepare functional foods. In this review, the recovery of polyphenols and fibers with green technologies from food waste for the formulation of functional foods was presented.

Zinc oxide nanoparticles cooperate with the phyllosphere to promote grain yield and nutritional quality of rice under heatwave stress

To address rising global food demand, the development of sustainable technologies to increase productivity is urgently needed. This study revealed that foliar application of zinc oxide nanoparticles (ZnO NPs; 30 to 80 nm, 0.67 mg/d per plant, 6 d) to rice leaves under heatwave (HW) stress increased the grain yield and nutritional quality. Compared with the HW control, the HWs+ZnO group presented increases in the grain yield, grain protein content, and amino acid content of 22.1%, 11.8%, and 77.5%, respectively. Nanoscale ZnO aggregated on the leaf surface and interacted with leaf surface molecules. Compared with that at ambient temperature, HW treatment increased the dissolution of ZnO NPs on the leaf surface by 25.9% and facilitated their translocation to mesophyll cells. The Zn in the leaves existed as both ionic Zn and particulate ZnO. Compared with the HW control, foliar application of ZnO NPs under HW conditions increased leaf nutrient levels (Zn, Mn, Cu, Fe, and Mg) by 15.8 to 416.9%, the chlorophyll content by 22.2 to 24.8%, Rubisco enzyme activity by 21.2%, and antioxidant activity by 26.7 to 31.2%. Transcriptomic analyses revealed that ZnO NPs reversed HW-induced transcriptomic dysregulation, thereby enhancing leaf photosynthesis by 74.4%. Additionally, ZnO NPs increased the diversity, stability, and enrichment of beneficial microbial taxa and protected the phyllosphere microbial community from HW damage. This work elucidates how NPs interact with the phyllosphere, highlighting the potential of NPs to promote sustainable agriculture, especially under extreme climate events (e.g., HWs).

MgAl-Layered Double Hydroxide-Coated Bio-Silica as an Adsorbent for Anionic Pollutants Removal: A Case Study of the Implementation of Sustainable Technologies.

The adsorption efficiency of Cr(VI) and anionic textile dyes onto MgAl-layered double hydroxides (LDHs) and MgAl-LDH coated on bio-silica (b-SiO2) nanoparticles (MgAl-LDH@SiO2) derived from waste rice husks was studied in this work. The material was characterized using field-emission scanning electron microscopy (FE-SEM/EDS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopic (XPS) techniques. The adsorption capacities of MgAl-LDH@SiO2 were increased by 12.2%, 11.7%, 10.6%, and 10.0% in the processes of Cr(VI), Acid Blue 225 (AB-225), Acid Violet 109 (AV-109), and Acid Green 40 (AG-40) dye removal versus MgAl-LDH. The obtained results indicated the contribution of b-SiO2 to the development of active surface functionalities of MgAl-LDH. A kinetic study indicated lower intraparticle diffusional transport resistance. Physisorption is the dominant mechanism for dye removal, while surface complexation dominates in the processes of Cr(VI) removal. The disposal of effluent water after five adsorption/desorption cycles was attained using enzymatic decolorization, photocatalytic degradation of the dyes, and chromate reduction, satisfying the prescribed national legislation. Under optimal conditions and using immobilized horseradish peroxidase (HRP), efficient decolorization of effluent solutions containing AB-225 and AV-109 dyes was achieved. Exhausted MgAl-LDH@SiO2 was processed by dissolution/precipitation of Mg and Al hydroxides, while residual silica was used as a reinforcing filler in polyester composites. The fire-proofing properties of composites with Mg and Al hydroxides were also improved, which provides a closed loop with zero waste generation. The development of wastewater treatment technologies and the production of potentially marketable composites led to the successful achievement of both low environmental impacts and circular economy implementation.

Machine Learning Approaches in Advancing Perovskite Solar Cells Research

AbstractThe integration of machine learning (ML) with perovskite solar cells (PSCs) signifies a groundbreaking era in photovoltaic (PV) technology. The traditional iterative approaches in PSC research are often time‐consuming and resource‐intensive. In contrast, ML leverages available data and sophisticated algorithms to quickly identify properties and optimize parameters for novel materials and devices. This review explores how ML‐driven approaches are improving various facets of PSCs research, including the rapid screening of novel compositions, enhancing stability, refining device architectures, and deepening the understanding of underlying physics. The paper is structured to gradually familiarize readers with essential terminologies and concepts, ensuring a solid foundation before delving into more intricate topics. A concise workflow and various introductory toolkits for ML are also briefly discussed. Through a detailed analysis of compelling case studies, a basic research framework within ML‐PSC‐integrated research is provided. This comprehensive review can serve as a valuable reference for researchers aiming to understand and leverage ML‐driven approaches in PSCs research, advancing the path for more efficient and sustainable PV technologies.

Technology Focus: EOR Operations (November 2024)

International agreements and national policies on environmental sustainability are changing the outlook for enhanced oil recovery (EOR) globally. These changes are highlighted by both monetary and intellectual commitments by oil companies around the world. Saudi Aramco has pledged $1.5 billion toward sustainable technology. In practice, members of Aramco’s EXPEC Advanced Research Center have collaborated with King Fahd University of Petroleum and Minerals to develop sustainable surfactants for use in high-temperature, high-pressure, and high-salinity carbonate reservoirs. They used no or only green solvents to produce soluble, stable surfactants with the potential for biodegradability. In Colombia, Ecopetrol is committed to reducing CO2 emission by 25% by 2030. As part of its efforts, it has been optimizing polymer injection in Chichimene, a heavy-oil field. By estimating life cycle greenhouse-gas emissions and energy consumption, it was able to show that polymer injection and its associated carbon intensity reduction could prevent the emission of 3,200 tons CO2 equivalent. To comply with the UK’s North Sea Transition Deal, which mandates a 50% reduction in offshore oil and gas emissions by 2030, Ithaca Energy and Energy Research Norway is using life-cycle assessment to guide more efficient heavy-oil recovery. By using low-dose polymer injection, instead of alternatives such as thermal EOR, it was able to increase exergy while also reducing CO2 emissions by 35%. In these studies, we already see the effect of the energy transition as companies turn away from traditionally effective but environmentally burdensome EOR methods such as steam injection and new polymers that show equal, if not greater, effectiveness with a reduced environmental cost. As we move forward with further regulation and innovation, it will be interesting to see how emerging technological developments in polymers, nanofluids, and even artificial intelligence can help producers meet both the economic and environmental criteria to maintain profitable fields. Recommended additional reading at OnePetro: www.onepetro.org. SPE 218653 Coinjection EOR Technology Increases Recovery and Reduces Greenhouse-Gas Emissions by G. Wasylchuk, GERI SPE 218690 Steam Generation Using Renewables Energy—An Integrated Approach for Enhanced Oil Recovery Applications by Mustafa Al Ajmi, Petroleum Development Oman, et al. SPE 218962 Reaching a Million Barrels in an Abu Dhabi Field by Focusing on Operations Efficiency by Masud J. Akhtar, Abu Dhabi National Oil Company, et al.

Overview of Baker's Yeast as a Biocatalyst

Biocatalysis is an approach to green chemistry. A crucial step in the synthesis of or-ganic compounds is the reduction of aldehydes and ketones to secondary alcohols. The use of a biocatalyst, such as enzymes or entire cells, has not affected this process.. It offers great selectiv-ity, high specificity, and an environmentally friendly approach to synthesis. Dried baker's yeast mediates the conversion of optically active alcohols from aromatic aldehydes and ketones. This work highlights applications of Baker's yeast in synthesizing pharmaceutical intermediates and chiral building blocks, demonstrating its practical relevance. Sustainable technology is based on the ideas and measurements of sustainable development and green for good enantioselectivity across several organic solvents.

Energy and exergy analysis of a multipass macro-encapsulated phase change material/expanded graphite composite thermal energy storage for domestic hot water applications

This study presents the development and performance evaluation of an innovative thermal energy storage (TES) system utilizing a commercially available bioderived organic phase change material (PCM) for domestic hot water production. The primary objective of this research is to enhance the efficiency and effectiveness of thermal energy storage solutions by macro-encapsulating the PCM-expanded graphite (EG) compressed modules in a multi-pass tube arrangement. A comprehensive experimental setup was employed to investigate the thermal performance of the proposed TES unit, focusing on charging and discharging cycles. Key findings reveal that conduction is the dominant mode of heat transfer, with the system achieving a significant maximum average charging power of 1440 W and a discharging power of 1990 W. The thermal energy storage capacity reached an impressive 12.6 MJ, enabling the discharge of 90 % of stored energy within 90 min. Furthermore, the exergy analysis indicated high exergy efficiencies, with charging efficiencies reaching 98 % and overall exergy efficiency at 18 %.The implications of this research are significant, demonstrating the feasibility of using bioderived organic PCM for sustainable energy applications. It highlights the potential of the modular structure of the system to integrate with heat pump and solar energy systems, thereby enhancing efficiency and sustainability in domestic hot water applications. This work significantly contributes to the advancement of sustainable thermal energy storage technologies and establishes a solid foundation for future studies aimed at optimizing TES systems for domestic hot water production.

Porous activated carbon electrodes derived from Eleusine coracana biowaste in electric double layer capacitors: Nanoarchitectonics and performance

The development of high-performance supercapacitors from biowaste is crucial for advancing sustainable and renewable energy storage technologies. In this study, we report the fabrication of electrodes for high-performance supercapacitors using porous carbon derived from red millet (Eleusine coracana) straw. Porous carbon was synthesized via a two-step chemical activation process using KOH, resulting in a hierarchical pore structure comprising macro-, meso-, and micropores. The red millet-based porous carbon electrodes, assembled in a two-electrode symmetrical supercapacitor, exhibited a specific capacitance of 68 Fg⁻1 at a current density of 0.5 Ag⁻1 in a 1 M Na₂SO₄ aqueous electrolyte. At a mass loading of 5 mg per electrode, the system demonstrated a specific capacitance of 300 Fg⁻1 at 1 Ag⁻1, with an energy density of 9.1 Whkg⁻1 and a power density of 1.86 kWkg⁻1, as determined from galvanostatic charge-discharge measurements. Additionally, the supercapacitor showed excellent cyclic stability, retaining 98.78% of its initial capacitance after 5000 cycles at 10 Ag⁻1. These findings highlight the potential of porous carbon derived from agricultural biowaste for scalable applications in electric double-layer capacitors.

Enhancing nanofiltration performance with tannic acid and polyvinyl alcohol interlayers for improved water permeability and selective solute rejection

Global water shortages have significantly intensified the demand for efficient and sustainable water purification technologies. Nanofiltration (NF) plays a crucial role in desalination, providing distinct advantages by removing a variety of pollutants including heavy metals and organic compounds, all while consuming minimal energy. Traditional NF membranes often struggle to balance high rejection with satisfactory permeability. This study advances NF technology by utilizing polysulfone as a durable substrate and introducing tannic acid (TA)-polyvinyl alcohol (PVA) interlayer to enhance structural robustness and functional capabilities of membranes. Through streamlined one-step coating followed by precise interfacial polymerization, this approach optimizes monomer piperazine storage and dispersion on substrate, effectively controlling its diffusion rate, resulting in a thinner polyamide (PA) layer. These strategic enhancements not only lead to a significant increase in permeability to 216.3 L·m−2·h−1·MPa−1 and an impressive rejection for Na2SO4 of 99.04 % but also ensure enhanced long-term operational stability. The innovative TA-PVA interlayer sets new benchmarks for high-performance NF membranes by combining environmental friendliness with cost-effectiveness, making it ideal for large-scale industrial applications. This unique composition promotes sustainability and economic efficiency in water treatment technologies, and underscoring the vast potential for expanding the production and application of advanced NF systems.