3,4-Ethylene dioxythiophene (EDOT), as a monomer of commercial conductive poly(3,4-ethylene dioxythiophene) (PEDOT), has been facilely incorporated into a series of new π-conjugated polymer-based photocatalysts, i.e., BSO2–EDOT, DBT–EDOT, Py–EDOT and DFB–EDOT, through atom-economic C–H direct arylation polymerization (DArP). The photocatalytic hydrogen production (PHP) test shows that donor–acceptor (D–A)-type BSO2–EDOT renders the highest hydrogen evolution rate (HER) among the linear conjugated polymers (CPs) ever reported. A HER up to 0.95 mmol h−1/6 mg under visible light irradiation and an unprecedented apparent quantum yield of 13.6% at 550 nm are successfully achieved. Note that the photocatalytic activities of the C–H/C–Br coupling-derived EDOT-based CPs are superior to those of their counterparts derived from the classical C–Sn/C–Br Stille coupling, demonstrating that EDOT is a promising electron-rich building block which can be facilely integrated into CP-based photocatalysts. Systematic studies reveal that the enhanced water wettability by the integration of polar BSO2 with hydrophilic EDOT, the increased electron-donating ability by O–C p–π conjugation, the improved electron transfer by D–A architecture, broad light harvesting, and the nano-sized colloidal character in a H2O/NMP mixed solvent rendered BSO2–EDOT as one of the best CP photocatalysts toward PHP.

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EDOT-based conjugated polymers accessed via C–H direct arylation for efficient photocatalytic hydrogen production

Z-scheme systems: From fundamental principles to characterization, synthesis, and photocatalytic fuel-conversion applications

Significant improving g-C 3 N 4 ’s photocatalytic efficiency still remains a great challenge. In this work, we synthesized ultrathin and porous 2D g-C 3 N 4 nanosheets with a controllable concentration of carbon vacancies and oxygen doping. Water vapor opens the heptazine units, introduces carbon vacancies, and acts as an oxygen source for oxygen doping under high temperatures. The synergistic effect of controllable carbon vacancies and oxygen doping can continuously regulate band structures and significantly improves the separation efficiency of photoexcited charges. As a result, the prepared g-C 3 N 4 with vigoroso reduction potential exhibits a very high photocatalytic H 2 evolution rate of 2.414 mmol g −1 h −1 under visible light and 7.414 mmol g −1 h −1 under ultraviolet-visible light, respectively, which outperforms the majority of the previously reported g-C 3 N 4 with well-tuned band structure. This work offers a new design idea for highly active g-C 3 N 4 -based photocatalysts with a well-tuned band structure. A step-by-step synergistic etching/stripping strategy is developed for preparing ultrathin and porous 2D g-C 3 N 4 nanosheets with controllable carbon vacancies and oxygen doping with a great potential in photocatalysis. • Ultra-thin and porous 2D g-C 3 N 4 nanosheets with controllable carbon vacancies and oxygen doping are prepared. • Water vapor opens the heptazine units, introduces carbon vacancies, and acts as oxygen sources for oxygen doping under high temperatures. • Synergistic effect of controllable carbon vacancies and oxygen doping can continuously regulate band structures. • Rapid separation of photoexcited charges and up-shift of conduction band boost photocatalytic performance.. 

Ultrathin Porous Carbon Nitride Nanosheets with Well-tuned Band Structures via Carbon Vacancies and Oxygen Doping for Significantly Boosting H2 Production

Solar H2 production systems: current status and prospective application

Interior and surface synergistic modifications can endow the photocatalytic reaction with tuned photogenerated carrier flow at the atomic level. Herein, a new class of 2D/2D SnNb2O6/Ni-doped ZnIn2S4 (SNO/Ni-ZIS) S-scheme heterojunctions is synthesized by a simple hydrothermal strategy, which was used to evaluate the synergy between interior and surface modifications. Theoretical calculations show that the S-scheme heterojunction boosts the desorption of H atoms for rapid H2 evolution. As a result, 25% SNO/Ni0.4-ZIS exhibits significantly improved PHE activity under visible light, roughly 4.49 and 2.00 times stronger than that of single ZIS and Ni0.4-ZIS, respectively. In addition, 25% SNO/Ni0.4-ZIS also shows superior structural stability. This work provides advanced insight for developing high-performance S-scheme systems from photocatalyst design to mechanistic insight.

Interior and Surface Synergistic Modifications Modulate the SnNb2O6/Ni-Doped ZnIn2S4 S-Scheme Heterojunction for Efficient Photocatalytic H2 Evolution.

Solar-driven fuel production is considered a promising strategy to solve the growing global energy demands and environmental problems. Z-scheme heterojunctions have been reported to exhibit considerably improved photocatalytic fuel production due to enhanced light harvesting, spatially separated reductive and oxidative active sites, and strong redox capability. Understanding the fundamental principles of Z-scheme photocatalytic systems and mastering their improvement strategies will help greatly with the further development of highly efficient Z-scheme photocatalysts for solar-driven fuel production and other photocatalytic applications. Z-scheme photocatalysts have recently received tremendous attention because of their strong light utilization and redox ability. This cutting-edge photocatalytic platform allows photocatalysts to convert light into chemical energy with high activity, selectivity, and stability. In this review, we highlight some of the recent key contributions in the field, including fundamental principles, advanced characterization methods, and a series of photocatalytic applications (e.g., water splitting, CO2 reduction, N2 fixation, H2O2 production). Significant improvement strategies for Z-scheme photocatalysts are also discussed and summarized. With increasing achievements, Z-scheme photocatalytic systems (PSs) will make a historic breakthrough in activity, solar utilization, selectivity, and fabrication cost and move toward practical production in the near future. Z-scheme photocatalysts have recently received tremendous attention because of their strong light utilization and redox ability. This cutting-edge photocatalytic platform allows photocatalysts to convert light into chemical energy with high activity, selectivity, and stability. In this review, we highlight some of the recent key contributions in the field, including fundamental principles, advanced characterization methods, and a series of photocatalytic applications (e.g., water splitting, CO2 reduction, N2 fixation, H2O2 production). Significant improvement strategies for Z-scheme photocatalysts are also discussed and summarized. With increasing achievements, Z-scheme photocatalytic systems (PSs) will make a historic breakthrough in activity, solar utilization, selectivity, and fabrication cost and move toward practical production in the near future. a typical layered 2D material with puckered layers of phosphorus stacked together via van der Waals forces. the energy band formed by free electrons. a unique class of materials that combine extended π-conjugation with a permanently microporous skeleton. one of the most widely used theoretical calculation technologies. a Z-scheme photocatalyst that shows photocatalytic activity under all wavelengths of light. an emerging 2D layered transition-metal carbide/carbonitride/nitride. metal–semiconductor contact that has a negligible contact resistance relative to the bulk or series resistance of the semiconductor. the charge-transfer route in S-scheme mode resembles a macroscopic ‘step’ (from low CB to high VB; Figure 1D). MoS2 with unsaturated S atoms on exposed edges as reactive sites forms three stacked atomic layers. the energy band formed by valence electrons. the minimum energy required to move an electron from the interior of a solid to its surface. the photogenerated carrier transfer route looks like the letter Z. 

Jörg Orgeldinger

Papers

Emerging frontiers of Z-scheme photocatalytic systems

Non-natural catalysts for catalytic tar conversion in biomass gasification technology

Fabrication of a novel nickel-nickel aluminate nanocomposite with improved nanoparticle dispersion