An efficient visible-light-driven photoconversion of nitrobenzene to aniline over PtO-decorated WO3 nanocrystals prepared by a soft template-based method

Background: Photocatalysis represent a green method for oxidation and reduction reactions. This method is initiated by exciting a semiconducting material by light resulting in electron-hole (e--h+) pair formation that contributes to chemical reactions. Using metal oxide photocatalysts is a green approach for selective organic transformation. Aniline (AN) is a joint compound in several chemical industries.Methods: This work presents a simple soft template-assisted synthesis of tungsten oxide (WO3) nanocrystals followed by adding trace amounts (0.1-0.4 wt.%) of platinum oxide (PtO) nanodots through precipitation. Significant findings: Physicochemical description of formed heterostructures unveiled the mesoporous surface texture construction and the significance of PtO inclusion on the optical and semiconducting properties of WO3. The PtO addition to WO3 at 0.3 wt.% confirms the considerable decrease of the bandgap energy from 2.74 to 2.36 eV, revealing the excellent visible light fascination. The PtO-decorated WO3 was performed to synthesize AN from NB by photoconversion. The optimal dose of 0.3% PtO/WO3 (2.0 gL-1) revealed a complete photo-conversion of NB into the beneficial AN within 40 min with magnificent reusability. The PtO loading demon-strates the enhanced e--h+ separation and mobilities. This study opens the door for plenty of research toward the realization of metal oxide-based heterostructures to produce industrial chemicals.

Automated summary

This study presents a simple method for the synthesis of tungsten oxide (WO3) nanocrystals with the assistance of a soft template, followed by the addition of trace amounts of platinum oxide (PtO) nanodots through precipitation. It is found that the addition of PtO can significantly change the optical and semiconductor properties of WO3, reducing the bandgap energy and enhancing its absorption of visible light. The PtO-decorated WO3 shows excellent photoconversion performance in the synthesis of aniline (AN), with high reusability. This study opens the door for further research on metal oxide-based heterostructures for the production of industrial chemicals.