H2 CO2 Research Articles

ZIF-8 metal-organic frameworks and their hybrid materials: emerging photocatalysts for energy and environmental applications.

In the face of escalating environmental challenges such as fossil fuel dependence and water pollution, innovative solutions are essential for sustainable development. In this regard, zeolitic imidazolate frameworks (ZIFs), specifically ZIF-8, act as promising photocatalysts for environmental remediation and renewable energy applications. ZIF-8, a subclass of metal-organic frameworks (MOFs), is renowned for its large specific surface area, high porosity, rapid electron transfer ability, abundant functionalities, ease of designing, controllable properties, and remarkable chemical and thermal stability. However, its application as a standalone photocatalyst is limited by issues such as particle aggregation, poor water stability, and insufficient visible light absorption. By integrating ZIF-8 with various photoactive materials to form composite catalysts, these drawbacks can be mitigated, leading to enhanced photocatalytic efficiency. The review discusses the synthesis, properties, and applications of ZIF-8-based photocatalysts in light-driven H2 evolution, H2O2 evolution, CO2 reduction, and dye and drug degradation. It also highlights the challenges and future research directions in developing cost-effective, scalable, and environmentally friendly ZIF-8 composites for industrial applications. The potential of ZIF-8 composites to contribute to sustainable global energy solutions and environmental cleanup is significant, yet further exploration is required to harness their capabilities thoroughly.

G-C3N4 S-Scheme Homojunction through van der Waals Interface Regulation by Intrinsic Polymerization Tailoringfor Enhanced Photocatalytic H2 Evolution and CO2 Reduction.

The effective S-scheme homojunction relies on the precise regulation of band structure and construction of advantaged charge migration interfaces. Here, the electronic structural properties of g-C3N4 were modulated through meticulous polymerization of self-assembled supramolecular precursors. Experimental and DFT results indicate that both the intrinsic bandgap and surface electronic characteristics were adjusted, leading to the formation of an in-situ reconstructed homojunction interface facilitated by intrinsic van der Waals forces. The homojunction catalyst, composed of g-C3N4 nanodots and ultra-thin g-C3N4 nanoflakes, exhibited a significant S-scheme carrier separation mechanism, which enhances the utilization of electrons and holes. Consequently, under AM 1.5 light irradiation (~100 mW/cm2), the g-C3N4 homojunction photocatalyst achieved a remarkable hydrogen evolution rate of 580 μmol h-1. Furthermore, a reversed CH4 selectivity in CO2 reduction was observed, yielding 80.30 μmol g-1 h-1 with a selectivity of 96.86%, in contrast to the performance of bulk g-C3N4, which produced only 2.22 μmol g-1 h-1 with the 15.69% CH4 selectivity. These findings not only highlight the significant potential of the g-C3N4 homojunction photocatalyst for hydrogen production and CO2 reduction but also propose a superior and effective strategy for optimizing the structural properties of g-C3N4, which are crucial for the design of photocatalytic reactions.

G‐C3N4 S‐Scheme Homojunction through van der Waals Interface Regulation by Intrinsic Polymerization Tailoring for Enhanced Photocatalytic H2 Evolution and CO2 Reduction

g‐C3N4 S‐Scheme Homojunction through van der Waals Interface Regulation by Intrinsic Polymerization Tailoring for Enhanced Photocatalytic H2 Evolution and CO2 Reduction

Porous Supramolecular Crystalline Materials for Photocatalysis.

Porous supramolecular crystalline materials (PSCMs), usually including hydrogen-bonded organic frameworks (HOFs), π frameworks, and so on, can be defined as a type of porous supramolecular assemblies stabilized by hydrogen-bonding, π-π stacking and other non-covalent interactions. Given the unique features of mild synthetic conditions, well-defined and tailorable structures, easy healing and regeneration, PSCMs have captured widespread interest in molecular recognition, sensor, gas storage and separation, and so on. Moreover, they currently emerge as promising photocatalysts because it is readily to endow PSCMs with photo-function, and the hydrogen-bonding and π-π stacking can serve as electron transfer channels to boost photocatalytic activity. Nevertheless, the research on PSCMs for photocatalysis is still at an early stage. A review on this topic will greatly promote the development of supramolecular chemistry. In this Minireview, we will firstly introduce the syntheses of PSCMs, and then highlight the advantages of PSCMs in photocatalysis. Following this, we will further summarize the photocatalytic applications of PSCMs toward CO2 reduction, H2 evolution, H2O2 production, organic transformation and pollution degradation, where emphasis will be placed on concluding the relationship between the catalyst performances and structures. Finally, we will discuss the remaining challenges and perspectives in developing high-performance PSCM-based photocatalysts.

Efficient photocatalytic CO2 reduction and H2 evolution on nitrogen vacancies enriched g-C3N4 treated by formic acid

Efficient photocatalytic CO2 reduction and H2 evolution on nitrogen vacancies enriched g-C3N4 treated by formic acid

Fast synthesis of Cu@zeolitic imidazolate framework-8 (ZIF-8) derived Cu/ZnO catalysts via a facile mechanical grinding method for CO2 hydrogenation to methanol.

Direct conversion of CO2 with renewable H2 to produce methanol provides a promising way for CO2 utilization and H2 storage. Cu/ZnO catalysts are active, but their activities depend on the preparation methods. Here, we reported a facile mechanical grinding method for the fast synthesis of Cu@zeolitic imidazolate framework-8 (ZIF-8) derived Cu/ZnO catalysts applied in CO2 hydrogenation to methanol. The confinement in ZIF-8 cages led to the formation of metal oxide particles with controlled crystallite sizes after pyrolysis in air. ZnO derived from ZIF-8 with ultrahigh specific surface area offered high CuO dispersion, obtaining higher Cu0 surface area and smaller Cu crystallite size after reduction. The effects of the Cu/(Cu + Zn) molar ratio and alcohol types during catalyst preparation on the textural properties of final catalysts were systemically studied. The resultant catalyst exhibited high activity with STY of methanol up to 128.7 g kgcat -1 h-1 at 200 °C, much higher than that of catalysts prepared by the conventional impregnation and coprecipitation methods and commercial Cu/ZnO. The present work offers an efficient method for optimizing Cu/ZnO catalysts for CO2 hydrogenation to methanol.

A recyclable T-ZIF-8/SnO2@PAN photocatalytic porous fibrous membrane used for CO2 reduction

The challenge of separating and recycling high-performance photocatalysts often results in resource wastage and secondary environmental contamination. Therefore, the advancement of recyclable photocatalysts has emerged as a frontier area of interest in the domain of photocatalytic CO2 reduction. In this work, T-ZIF-8/SnO2@PAN-PVP fibrous membranes were constructed with T-ZIF-8/SnO2 as a photocatalyst, polyacrylonitrile (PAN) as a matrix, polyvinylpyrrolidone (PVP) as a porogen utilizing electrospinning technique. By regulating the variable parameters, the effects of spinning solution concentration, conductive salt dosage, porogenic agent dosage and their effects on fiber microscopic morphology were investigated, and the process parameters were optimized to obtain the best microscopic morphology, and then the photocatalytic porous fibers were obtained through the water impregnation treatment. A comparative analysis of the CO2 reduction capability of photocatalytic powders, fibers, and porous fibers was performed, alongside an exploration of the potential reaction mechanism. The results indicate that the T-ZIF-8/SnO2@PAN-PVP porous fiber membrane irradiated by visible light for 4 h demonstrates excellent CO2 reduction efficiency, achieving CO, CH4, and H2 production rates of 14.3, 7.09, and 8.57 μmol·g−1·h−1, respectively. Durability tests through repetitive experiments have validated that the T-ZIF-8/SnO2@PAN/ZnCl2 porous fiber membrane retains over 90 % of its initial photocatalytic activity after four cycles, thereby facilitating the sustainable recycling and reuse of photocatalysts.

Ecologic and Economic Evaluation of Combined Methanol Synthesis from CO2 and Biotechnological Upgrading to Value Products. Part 1: Environmental Impact

AbstractThe conversion of waste biomass with green hydrogen into methanol and subsequent biotechnological conversion of this into valuable materials could be a promising value chain. Starting from biogenic CO2 and green H2, methanol is produced in a first process path. This is then split into two separate process paths: methanol is used (i) in a biotechnological process with genetically modified bacteria to produce crotonic acid and (ii) to produce biomass protein. To evaluate the ecologically and economic benefits of both biological processes to the conventional production routes, first life cycle assessment and techno‐economic assessment of biotechnological and chemical processes are accomplished. For this, a baseline scenario and several scenarios are calculated to investigate the influence of various parameters on environmental impact and economic efficiency. The results also identify the processes that are mainly responsible for costs and environmental impact, as well as the material, energy and waste flows, and process parameters that cause them. From this, measures and conditions for improving economic efficiency and environmental impact are derived.

Advances in Artificial Photosynthesis: The Role of Chalcogenides and Chalcogenide‐Based Heterostructures

AbstractArtificial photosynthesis, encompassing the photocatalytic generation of H2 and CO2 reduction innovations, seems to be a highly promising approach. This is due to its ability to efficiently transform CO2 into hydrocarbon fuel and valuable chemical products using solar energy as a direct energy source. This will simultaneously help to mitigate global warming and energy shortage issues. Chalcogenide‐based semiconductors have recently gotten a lot of attention as an important area of research for photocatalytic H2 production and CO2 conversion, owing to their low band gap energy, suitable band structures, and a great photoresponsivity spectrum. Modifying chalcogenides into their heterostructures could be a great way to solve problems like photo corrosion and carrier recombination. Therefore, this review summarized a series of different modifications of chalcogenides and recent developments in their photocatalytic and photo electrocatalytic performance, particularly in H2 production and CO2 conversion. Lastly, we discussed the challenges, limitations, areas for development, and future prospects of chalcogenides and their heterostructures capable of utilizing visible light to produce H2 gas and reduce CO2.

Selective Carbon Monoxide-Gas-Sensing Properties over CuO/Rb<sub>2</sub>CO<sub>3</sub> Nanohybrid Structure

CuO/Rb2CO3 nanohybrid structures are fabricated, and their selectivity to CO over H2 as well as related sensing mechanisms are investigated. A series of CuO/Rb2CO3 nanohybrid structures are deposited on alumina substrates by the bar-coating method. The chemical, morphological, and structural properties of the nanohybrid structures are examined by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and Raman spectroscopy. The best selectivity to CO over H2 and highest CO response level are observed upon CuO/Rb2CO3 nanohybrid (5 wt.% Rb2CO3). The gas-sensing performance of the CuO/Rb2CO3 hybrid nanostructures is analyzed to prove that the catalytic properties of Rb2CO3 and its modulation ability to hole accumulation layer thickness of CuO determine the outstanding selectivity and high response level of CuO/Rb2CO3 nanohybrid structure compared to pristine CuO nanoparticles.

Two-Dimensional Conjugated Metal-Organic Frameworks for Photochemical Transformations.

Photochemical transformation represents an attractive pathway for the conversion of earth-abundant resources, such as H2O, CO2, O2, and N2, into valuable chemicals by utilizing sunlight as an energy source. Recently, two-dimensional conjugated metal-organic frameworks (2D c-MOFs) have emerged as the focal points in the field of photo-to-chemical conversion due to their advantages in light harvesting, electrical conductivity, mass transport, tunable electronic and porous structures, as well as abundant active sites. In this review, we highlight various physical and chemical features of 2D c-MOFs that can contribute to enhanced photo-induced exciton generation, charge transport, proton migration and redox catalysis. Then, the existing strategies to integrate suitable light absorbers and/or co-catalysts onto 2D c-MOFs for photochemical transformations (with a particular focus on H2 evolution, CO2 reduction and O2 reduction) have been discussed. Finally, the challenges and opportunities of using 2D c-MOFs in other photochemical applications (e.g., N2 fixation, organic synthesis, and environmental remediation) are assessed.

Two‐Dimensional Conjugated Metal‐Organic Frameworks for Photochemical Transformations

Photochemical transformation represents an attractive pathway for the conversion of earth‐abundant resources, such as H2O, CO2, O2, and N2, into valuable chemicals by utilizing sunlight as an energy source. Recently, two‐dimensional conjugated metal‐organic frameworks (2D c‐MOFs) have emerged as the focal points in the field of photo‐to‐chemical conversion due to their advantages in light harvesting, electrical conductivity, mass transport, tunable electronic and porous structures, as well as abundant active sites. In this review, we highlight various physical and chemical features of 2D c‐MOFs that can contribute to enhanced photo‐induced exciton generation, charge transport, proton migration and redox catalysis. Then, the existing strategies to integrate suitable light absorbers and/or co‐catalysts onto 2D c‐MOFs for photochemical transformations (with a particular focus on H2 evolution, CO2 reduction and O2 reduction) have been discussed. Finally, the challenges and opportunities of using 2D c‐MOFs in other photochemical applications (e.g., N2 fixation, organic synthesis, and environmental remediation) are assessed.

Effect of High Voltage Electrode Material on Methanol Synthesis in a Pulsed Dielectric Barrier Discharge Plasma Reactor

Plasma methanol synthesis from captured CO2 and renewable H2 is one of the most promising technologies that can drastically lower the carbon footprint in methanol production, but the associated high energy costs make it less competitive. Herein, we investigated the impact of the high-voltage electrode configuration on methanol formation. The effect of electrode materials Cu, Al, and stainless steel (SS) SUS304 on CO2 hydrogenation to methanol using a temperature-controlled pulsed dielectric barrier discharge (DBD) plasma reactor was examined. The electrode surface area (ESA) was varied from 157 mm2 to 628 mm2 to determine the effect on discharge characteristics and the overall influence of plasma surface reactions on methanol production. The Cu electrode showed superior methanol synthesis performance (0.14 mmol/kWh) which was attributed to its catalytic activity function, while the Al electrode had the least production (0.08 mmol/kWh) ascribed to the excessive oxide coating on its surface, passivating its ability to promote methanol synthesis chemical reactions. In all electrode materials, the highest methanol production was achieved at 157 mm2 ESA at a constant applied voltage. Lastly, the plasma charge concentration per discharge volume was determined to be an important parameter in fine-tuning the DBD reactor to enhance methanol synthesis.

Hydrogen-rich gas generation from enhanced catalytic cracking of biomass tar and related model compounds on Ni-Fe/ASA@HZSM-5 catalyst: Pathways and mechanisms

This study focused on the design of complex tar model compounds (CTMC) and synthesized a highly efficient aluminum dross (ASA) combined with HZSM-5 molecular sieve co-loaded bimetallic Ni-Fe catalyst (Ni-Fe/ASA@HZSM-5), comprehensively evaluated the catalytic cracking of real tar and its model compound by adjusting the injection amount and injection state of tar, and catalyst types to obtain hydrogen-rich gas with high H2 and low CO2 content. The results showed under the conditions of the injection amount of 0.6 mL/min, pyrolysis temperature of 600 °C, reforming temperature of 800 °C in the liquid phase, Ni-Fe/ASA@HZSM-5 displays excellent catalytic cracking performance with CTMC conversion efficiency of 87.80 % (79.46 % of gas yield and 34.20 vol% of H2 yield). The possible cracking paths between different components of CTMC in the Ni-Fe catalytic system were summarized by the experimental data and product distribution, the catalytic mechanism of Ni–Fe based catalysts can be attributed to the formation of a Ni-Fe alloy and the synergistic effect of ASA and HZSM-5 co-carrier. Further, the catalytic cracking pathway of CTMC was enhanced in the gas phase, the higher CTMC conversion efficiency of 93.68 %, gas yield (a mass fraction of 82.51 %) and H2 (a volume fraction of 33.59 %) were obtained from catalytic cracking of CTMC, the liquid yield decreased by 12.39 %, significantly improved the cracking degree and gas production capacity of CTMC. The real tar showed the same catalytic pyrolysis path and product distribution. Under the same cracking conditions, the yields of gas, liquid and char were 84.85 %, 12.00 % and 3.15 % respectively, and obtained the hydrogen yield of 55.29 mL/g. The CTMC simplifies the cracking process and reduces polymerization, provides insights into the cracking mechanisms of heavy components in biomass tar. Furthermore, the synergy of Ni and Fe contributed to greater activity for CTMC and real tar cracking, ASA combined with HZSM-5 molecular sieve co-loaded bimetallic Ni-Fe catalysts have a promising application potential as highly efficient catalysts for tar removal and reutilization.

Water process/treatment by a S-scheme Fe2O3/TiO2 heterojunction photocatalyst for excellent antibiotic degradation/CO2 reduction/H2 production; process optimization and mechanistic insights

A facile synthesis approach was employed to fabricate a binary Fe2O3/TiO2 nanocomposite (FeTi4-400) for enhanced photocatalytic hydrogen (H2) production, cephalexin degradation and CO2 reduction under visible light irradiation. Compared to pristine TiO2, FeTi4-400 exhibited improved visible light absorption and promoted charge carrier separation, leading to increased H2 production rate and CO2 conversion into CH4 and CO. This improvement can be attributed to the formation of an S-scheme heterojunction, along with the desirable properties of FeTi4-400, including visible light activity, high surface area, and strong CO2 adsorption. The photocatalyst achieved a maximum H2 production rate of 649 μmol/g·h−1, exceeding that of pure TiO2. Similarly, the highest CO production rate of 16.44 μmol/g·h−1 was attained with FeTi4-400. Furthermore, FeTi4-400 achieved excellent cephalexin degradation (96 %) under optimal conditions, with a degradation rate constant of 0.01 min−1. A plausible cephalexin degradation pathway over FeTi4-400 is proposed. Transient photocurrent measurements and EIS analysis corroborated a significant enhancement in photocatalytic activity for FeTi4-400, attributed to the efficient separation of photogenerated electron-hole pairs. Stability studies demonstrated consistent cephalexin degradation by FeTi4-400 over five consecutive cycles without noticeable photocatalyst deactivation. This work presents a novel strategy for fabricating low-cost, efficient, and readily synthesized nanomaterials for applications in solar energy conversion and environmental remediation.

Overturning CO2 Hydrogenation Selectivity from CH4 to CO by Strong Ru-FeOx Interaction Arising from a Multilayer Epitaxial Structure.

The catalytic conversion of CO2 to CO through hydrogenation has emerged as a promising strategy for CO2 utilization, given that CO serves as a valuable C1 platform compound for synthesizing liquid fuels and chemicals. However, the predominant formation of CH4 via deep hydrogenation over Ru-based catalysts poses challenges in achieving selective CO production. High reaction temperatures often lead to catalyst deactivation and changes in selectivity due to dynamic metal evolution or agglomeration, even with a classic strong metal-support interaction. Herein, we have developed a FeOx/Ru/Rutile multilayer epitaxial structure by depositing a FeOx layer onto the epitaxially grown RuO2 nanolayers on the surface of rutile nanoparticles. This multilayer epitaxial structure transformed into a structure in which Ru nanoparticles were decorated with FeOx layers with ultrastable strong metal-support interaction (SMSI). Subsequently, the FeOx decoration on Ru nanoparticles effectively shifted the dominant product from CH4 to 95% CO during CO2 hydrogenation. Remarkably, this catalyst exhibits exceptional stability and can be operated stably at 550 °C for a long time without apparent deactivation. Compared with the dynamic changes observed in supported Ru nanoparticles, the interaction between Ru and FeOx maintains their electronic states at different reaction temperatures. Furthermore, this Ru-FeOx interaction inhibits H2 activation capability, CO adsorption, and subsequent hydrogenation of CO. The transformation strategy employed here, which utilizes initial multilayer epitaxial structures, can be applied to construct SMSI to enhance metal catalysts' catalytic performance.

Phase-Selective Synthesis of Cobalt Oxide Materials Via Electrochemical Chloride-Mediated Oxidation

The rapid growth of the global economy has led to an elevating human demand for energy and chemicals, which is heavily reliant on the utilization and conversion of fossil fuels. Electrochemical conversion is arising as a viable strategy for synthesizing a various high-value chemicals thanks to the mild operation conditions, adjustable selectivity, and potential for scalability in industrial settings. Chlor-alkali process can be utilized for removing microorganisms, disinfecting water, and so on. Furthermore, in an electrochemical system, the oxidation half reaction of the chloride oxidation can be coupled with a value-added reduction in half reaction, such as H2 evolution, N2 reduction, CO2 reduction, and organic reduction.In this study, β-CoOOH and γ-CoOOH, distinct cobalt oxyhydroxides, were synthesized via a chloride-mediated electrochemical oxidation process. This method employed heterogeneous reactions, where the oxidation of metal hydroxides was facilitated by electrochemically generated oxidants—active chlorine species—directly formed on the electrode surface through the oxidation of chloride ions. Characterization through X-ray diffraction (XRD) confirmed the synthesis of these two distinct metal oxide phases, elucidating their phase purity and crystal structures. Furthermore, the adjustable surface morphology and composition of intercalated ions were observed under varying electrosynthetic conditions. This synthetic strategy can be extended to the fabrication of other metal oxides, including manganese oxides. The resulting cobalt oxyhydroxide and manganese dioxide materials display versatile properties suitable for a wide range of applications in energy, environmental, and biotechnological fields.

Combined Electrolysis of Seawater and Wastewater for Decentralized Water Reuse and H2 Production

The current societal pursuit towards carbon neutrality would necessitate self-contained systems, ultimately to be independent on the existing water and energy grid. On-site wastewater treatment and reuse can reduce water and waste transportation, in-turn decreasing the carbon footprint for sanitation and hygiene. Electrochemical oxidation processes (EOPs) have emerged as a promising way of decentralized treatment of toilet wastewater and effluent reuse. On the other hand, a distributed and point-of-use electrolysis of locally available, nontraditional water sources including wastewater (effluent) can be involved within the H2 economy, reducing costs and CO2 emission from H2 transportation. This study proposes wastewater electrolysis cells (WECs) for localized wastewater treatment coupled with conversion of redundant renewable energy into H2. In the single-compartment WEC, therefore, oxygen reduction reaction competes with the hydrogen evolution reaction (HER), substantially decreasing the current and energy efficiency. Relatively low-grade H2 (< 60%) in mixture with N2 and CO2 can be utilized by combustion. This approach might be more available and appropriate practice in household and community level. This presentation also introduces recent electrocatalysts to overcome the bottlenecks of WEC such as requirements of precious elements based electrocatalysts and unsatisfactory selectivity of chlorine evolution reaction. These includes i) NiFe2O4 and CoSb2O6 with tiny amounts of Ir, and ii) precious metal cations (Ru and cocatalysts) atomically anchored on Magneli phase Ti4O7.

In-Situ Visualization and Quantification of Precipitate Fouling on Gas-Diffusion Electrodes in Carbon-Containing and Ocean Water Electrolytes

Proton coupled electron transfer reactions that change the pH at electrode-electrolyte interfaces are at the heart of many electrochemical reactions. Specifically, an increase in pH accompanies H2 evolution and CO2 reduction with relevance to fuels production from water and CO2 electrolysis or pH-swing processes for CO2 removal. When this increase in pH occurs in carbon-containing and/or ocean water electrolytes, it leads to salt precipitation and fouling in porous electrodes. Magnesium hydroxide and calcium carbonates are suspected precipitates in ocean water solutions, while potassium carbonates are the only possible precipitates in many CO2 reduction scenarios. This study develops and experimentally demonstrates a custom H-cell design that enables in-situ visualization of pH changes occuring during hydrogen evolution from a commercially available 0.5 mg/cm2 Pt-C carbon paper gas-diffusion electrode. Bulk pH is measured by a pH probe and this is used to calculate a local pH, based on the Nernst diffusion layer thickness. Fouling extents are further characterized through optical visualization of the surface and the chemical composition is characterized by tracking characteristic absorption peaks in the infrared spectra. Experiments are conducted at several different current densities to explore the effect of local pH on the rate and extent of precipitate formation and dissolution. Results reveal that fouling due to the formation of hydroxide precipitates occurs on electrode surfaces, even when the bulk pH conditions are not large enough to cause precipitation. This underscores the necessity to track local pH conditions. Results also demonstrate the significant precipitation observed in ocean water solutions with relevance to ocean water electrolysis and oceanic CO2 removal, as compared to solutions buffered with bicarbonate ions. Initial results also indicate how the rate of precipitate formation and removal from the porous surface is connected to the current density and pH conditions.

(Invited) Group III-Nitride Nanostructures and Devices: From Classical Optoelectronics to Artificial Photosynthesis

Third generation, group III-nitrides (InN, GaN, AlN and their alloys) semiconductor nanostructures have emerged as an important class of materials for a host of critical applications ranging from classical optoelectronics to quantum to artificial photosynthesis (i.e., photo(electro) chemical water splitting and CO2 reduction). Group III-nitrides exhibit unique properties including broad, tunable, direct energy bandgap, large exciton binding energy, giant spontaneous and piezoelectric polarization field, perfect conduction/valence band edge positioning to drive the redox reactions for fuel productions, interesting surface/interface properties, making them the only materials of choice for the afore-mentioned applications. In this talk, I will first present some recent advances of their epitaxy growth/synthesis, electronic, optical, and quantum properties, including the development of high efficiency visible and deep UV LEDs/laser diodes, and the realization of monolithic micro-LEDs.A highly efficient and robust artificial photosynthesis integrated device and system (APIDS) is the key for achieving carbon-neutral alternative to fossil fuels. III-nitrides can be used as an ideal building block of APIDS because of their recently discovered photocatalytic properties demonstrating great potential in artificial photosynthesis compared to decade long studied photocatalysts. Herein, the most recent advance in the utilization of III-nitrides-based artificial leaves for building a carbon-neutral substance and energy recycling system will be presented, focusing on solar water splitting toward H2 and solar CO2 reduction toward fuels and chemicals. I will also present on III-nitrides nanostructures-based non-classical on-demand quantum light sources (single photon and entangled photons sources) generation and their usage in quantum communication and optical quantum computing protocols. Overall, the talk focuses on the unique potential of group III-nitrides materials for emerging applications.