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Photocatalytic reduction of CO2 with H2O provides a promising and sustainable pathway to produce valuable chemicals and fuels. However, the low efficiency of CO2 reduction and the concomitant competition of H2 evolution pose serious challenges to practical applications. Herein, a novel approach is proposed to modulate the surface microenvironment of photocatalysts by utilizing hydrogen peroxide (H2O2). A bronze‐phase TiO2 (TB) composed of ultrathin nanosheet with a thickness of ∼3 nm is fabricated and employed as the model catalyst for photocatalytic CO2 reduction. H2O2 molecules are presumed to be bonded to the ultrathin TB surface to form the TB‐H2O2 (TBHO) active specie. The newly generated TBHO enhances the CO2 adsorption and accelerates mass transfer, and the weakly acidic microenvironment of the catalyst surface serves the purpose of mediating the proton‐coupled electron transfer path. Consequently, ultrathin TB nanosheets assisted by H2O2 show an excellent CO generation rate of 29.1 µmol−1 g−1 h−1 (which is 11.2‐fold higher than that of pure TB) in water, and the selectivity toward CO is nearly 100%. This work underscores the importance of tailoring the catalyst surface microenvironment to promote the CO2 reduction while minimizing the H2 generation in pure water. [ABSTRACT FROM AUTHOR]

Coenzyme NADH regeneration is crucial for sustained photoenzymatic catalysis of CO2 reduction. However, light‐driven NADH regeneration still suffers from the low regeneration efficiency and requires the use of a homogeneous Rh complex. Herein, a Rh complex‐based electron transfer unit was chemically attached onto the linker of the MIL‐125‐NH2. The coupling between the light‐harvesting iminopyridine unit and electron‐transferring Rh‐complex facilitated the photo‐induced electron transfer for the NADH regeneration with the yield of 66.4 % in 60 mins for 5 cycles. The formate dehydrogenase was further deposited onto the hydrophobic layer of the membrane by a reverse filtering technique, which forms the gas‐liquid‐solid reaction interface around the enzyme site. It gave an enhanced formic acid yield of 9.5 mM in 24 hours coupled with the in situ regenerated NADH. The work could shed light on the construction of integrated inorganic‐enzyme hybrid systems for artificial photosynthesis. [ABSTRACT FROM AUTHOR]

Hollow TiO 2 hierarchical boxes with suitable anatase and rutile ratios were designed for photocatalysis. The unique hierarchical structure was fabricated via a Topotactic synthetic method. CaTiO 3 cubes were acted as the sacrificial templates to create TiO 2 hollow hierarchical boxes with well-defined phase distribution. The phase composition of the hollow TiO 2 hierarchical boxes is similar to that of TiO 2 P25 nanoparticles (∼80% anatase, and 20% rutile). Compared with nanaoparticles, TiO 2 hollow boxes with hierarchical structures exhibited an excellent performance in the photocatalytic degradation of methylene blue organic pollutant. Quantificationally, the degradation rate of the hollow boxes is higher than that of TiO 2 P25 nanoparticles by a factor of 2.7. This is ascribed that hollow structure provide an opportunity for using incident light more efficiently. The surface hierarchical and well-organized porous structures are beneficial to supply more active sites and enough transport channels for reactant molecules. The boxes consist of single crystal anatase and rutile combined well with each other, which gives photon-generated carriers transfer efficiently. [ABSTRACT FROM AUTHOR]

Ag nanowire@TiO2 (Ag NW@TiO2) heterostructures with core-shell, necklace-like, and particle-decorated morphologies were fabricated to investigate the evolution of the photocatalytic properties. The deposition of the TiO2 phase on the surface of the Ag NWs was achieved through a solvothermal method. Thioglycolic acid (TGA) not only solves the tricky issue of substantial lattice mismatch between the Ag NW core and TiO2 shell, but also plays an important role in precisely controlling how the TiO2 is coated on the Ag NW surface. H2O molecules affect the deposition of the TiO2 phase on the Ag NWs. The photocatalytic activity of the Ag NW@TiO2 heterostructures with different morphologies was evaluated by degradation of methyl orange. The molar ratio of TiO2 to Ag is crucial for the photocatalytic activity, and the Ag NW@TiO2 sample with core-shell structure exhibits an excellent performance compared with the others, owing to the TiO2 phase being densely attached to the Ag NW surface, which forms a well-developed combined interface. [ABSTRACT FROM AUTHOR]