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Photocatalysis is the most promising method for achieving artificial photosynthesis, but a bottleneck is encountered in finding materials that could efficiently promote the water splitting reaction. The nontoxicity, low cost, and versatility of photocatalysts make them especially attractive for this application. This study demonstrates that small amounts of α-Fe2O3 nanosheets can actively promote exfoliation of g-C3N4, producing 2D hybrid that exhibits tight interfaces and an all-solid-state Z-scheme junction. These nanostructured hybrids present a high H2 evolution rate >3 × 104 µmol g-1 h-1 and external quantum efficiency of 44.35% at λ = 420 nm, the highest value so far reported among the family of g-C3N4 photocatalysts. Besides effectively suppressing the recombination of electron-hole pairs, this Z-scheme junction also exhibits activity toward overall water splitting without any sacrificial donor. The proposed synthetic route for controlled production of 2D g-C3N4-based structures provides a scalable alternative toward the development of highly efficient and active photocatalysts. [ABSTRACT FROM AUTHOR]

Abstract: Robust Gd–La codoped TiO2 microspheres with diameter of 2∼3 μm were successfully synthesized via a hydrothermal method using poly(ethylene glycol)-block–poly(propylene glycol)-block–poly(ethylene glycol) as a template. The photocatalytic activity of the Gd–La codoped TiO2 microspheres evaluated by photodegrading methyl orange (MO) has been significantly enhanced compared to that of undoped TiO2 microspheres. Ti4+ may substitute for La3+ and Gd3+ in the lattices of rare earth oxides to create abundant oxygen vacancies and surface defects for electron trapping and dye adsorption, accelerating the separation of photogenerated electron–hole pairs and MO photodegradation. The formation of an exciton energy level below the conduction band of TiO2 from the binding of electrons and oxygen vacancies decreases the excitation energy of Gd–La codoped TiO2 microspheres, resulting in robust photocatalysts. The results suggest that Gd–La codoped TiO2 microspheres calcined at 350 °C are very promising for enhancing the photocatalytic activity of photocatalysts. [Copyright &y& Elsevier]

Efficient separation of hole-electron pair plays a crucial role in enhancing photocatalytic water splitting activity, which essentially requires a noble metal co-catalyst. Here we report that two-dimensional (2D) metallic 1T-MoS 2 can exceed the performance of noble metal like Pt as a co-catalyst in assisting the photocatalytic hydrogen evolution over 2D semiconductor such as oxygenated monolayer graphitic carbon nitride (O-g-C 3 N 4 ). The abundance of intrinsic active site for hydrogen evolution reaction for 1T-MoS 2 partly contributes to the outstanding performance of 1T-MoS 2 /O-g-C 3 N 4 system. More importantly, the 2D heterostructure junction of 2D metals-2D semiconductor through van der Waals interaction minimizes the Schottky barrier, which in turn improves the charge transfer efficiency. The optimal 1T-MoS 2 /O-g-C 3 N 4 exhibited H 2 evolution rate as high as ∼1841.72 μmol/g/h, an external quantum efficiency of ∼7.11% at λ = 420 nm, and a super high TOF of 156.6 h −1 . [ABSTRACT FROM AUTHOR]