In this work, CdS quantum dots (QDs) supported on Ga2O3 and In2O3 are applied for visible-light-driven H2 evolution from aqueous solutions that contain lactic acid. With Pt as the cocatalyst, the H2 evolution rates on CdS/Pt/Ga2O3 and CdS/Pt/In2O3 are as high as 995.8 and 1032.2 μmol h(-1), respectively, under visible light (λ>420 nm) with apparent quantum efficiencies of 43.6 and 45.3% obtained at 460 nm, respectively. These are much higher than those on Pt/CdS (108.09 μmol h(-1)), Pt/Ga2O3 (0.12 μmol h(-1)), and Pt/In2O3 (0.05 μmol h(-1)). The photocatalysts have been characterized thoroughly and their band structures and photocurrent responses have been measured. The band alignment between the CdS QDs and In2O3 can lead to interfacial charge separation, which cannot occur between the CdS QDs and Ga2O3. Among the various possible factors that contribute to the high H2 evolution rates on CdS/Pt/oxide, the surface properties of the metal oxides play important roles, which include (i) the anchoring of CdS QDs and Pt nanoparticles for favorable interactions and (ii) the efficient trapping of photogenerated electrons from the CdS QDs because of surface defects (such as oxygen defects) based on photoluminescence and photocurrent studies.

A variety of ternary nanoheterostructures composed of Pt nanoparticles (NPs), SnOx species, and anatase TiO2 are designed elaborately to explore the effect of interfacial electron transfer on photocatalytic H2 evolution from a biofuel-water solution. Among numerous factors controlling the H2 evolution, the significance of Pt sites for the H2 evolution is highlighted by tuning the loading procedure of Pt NPs and SnOx species over TiO2. A synergistic enhancement of H2 evolution can be achieved over the Pt/SnOx/TiO2 heterostructures formed by anchoring Pt NPs at atomically-isolated Sn-oxo sites, whereas the Pt/TiO2/SnOx counterparts prepared by grafting single-site Sn-oxo species on Pt/TiO2 show a marked decrease in the rate of H2 evolution. The characterization results clearly reveal that the synergy of Pt NPs and SnOx species originates from the vectorial electron transfer of TiO2 → SnOx → Pt occurring on the former, while the latter results from the competitive electron transfer from TiO2 to SnOx and to Pt NPs.

No abstract

Herein, we reported a octahedral Cd3(C3N3S3)2 coordination polymer as a new noble metal-free photocatalyst for robust photocatalytic H2O2 production from methanol/water solution. The coordination polymer can give an unprecedented H2O2 yield of ca. 110.0 mmol • L−1 • g−1 at pH = 2.8 under visible light illumination. The characterization results clearly revealed that the photocatalytic H2O2 production proceeds by a pathway of two-electron reduction of O2 on the catalyst surface. This work showed the potential perspective of Mx(C3N3S3)y (M = transitional metals) coordination polymers as a series of new materials for solar energy storage and conversion.

The alkaline earth metal stannates MSnO3 (M = Ca, Sr, and Ba) photocatalysts with different morphologies are successfully prepared by hydrothermal method and their photocatalytic activities are evaluated by photocatalytic reforming of ethanol/water solution to hydrogen.