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The high cost of noble metal catalysts has been a great bottleneck for the catalyst industry. Using the noble metal at a single-atom level for catalytic applications could dramatically decrease the cost. The impacts of single Pt atoms on the photocatalytic performance of Ag3VO4 have been investigated and reported. In this report, single Pt atoms were anchored on the surface of Ag3VO4 (AVO) as a cocatalyst, and the resultant composite photocatalyst has been studied for photocatalytic H2 production from water driven by visible light. The as-prepared AVO particles are hollow nanospheres in the monoclinic phase with a bandgap of 2.20 eV. The light absorption edge of AVO/Pt is slightly red-shifted compared to that of the pristine AVO, indicating more visible light absorption of AVO/Pt. The XPS peaks of Ag, V, and Pt exhibit a significant shift after AVO and Pt get into contact, suggesting the strong interaction between the surface Ag and V atoms, and single Pt atoms. After 3-h illumination, the photocatalytic H2 evolution amount from AVO/Pt is improved up to 1400 μmol, which is 2.8 times that on the bare AVO. Such efficient photocatalytic H2 evolution on AVO/Pt is still maintained after five reaction cycles. The better photocatalytic performance of AVO/Pt has been attributed to the more efficient visible light utilization and the lower interfacial charge transfer resistance, as demonstrated in the DRS and EIS spectra. The presence of the surface Pt atoms also leads to a higher amount of reactive radicals, which could efficiently promote the surface redox reactions.

In this work we adopted, a facile method to synthesis Pd/CeO2/TiO2 nanocomposite in large scale and evaluated its catalytic property towards the benzene hydroxylation into phenol. The as-synthesized Pd/CeO2/TiO2 composite was vigilantly investigated using XRD, SEM, TEM, elemental mapping, XPS, TGA and BET studies. The uniformly dispersed Pd/CeO2/TiO2 with size 5–20 nm shows the high benzene conversion of 73% with 95% selectivity of phenol at 80 °C. The influence of various reaction conditions such as role of solvents, temperature, benzene to peroxide molar ratio, reaction time, etc were specifically investigated. The catalyst also showed pronounced photocatalytic activity for hydroxylation of benzene under the visible light conditions. The heterogeneity of the catalyst was additionally confirmed by Sheldon’s hot filtration test where no leaching up to 5 cycle, confirming the heterogeneity of the catalyst.