Enhancing Green Product Generation of Photocatalytic NO Oxidation: A Case of WO Nanoplate/g-CN S-Scheme Heterojunction.

Nitric oxide (NO) removal by photocatalytic oxidation over g-CN has achieved more efficient results. However, there is a concern about the high NO-to-NO conversion yield of products, which is not suitable for the photocatalytic NO reaction. In this study, we modify g-CN by WO nanoplates for the first time for photocatalytic NO oxidation over a WO/g-CN composite to enhance the green product selectivity under atmospheric conditions. The results indicate that the photocatalytic efficiency for NO removal by the WO/g-CN composite is drastically improved and achieves 52.5%, which is approximately 2.1 times higher than that of pure g-CN. Significantly, the green product (NO) selectivity of the WO/g-CN composite is 8.7 times higher than that of pure g-CN, and the selectivity remained high even after five cycles of photocatalytic tests. We also conclude that the enhanced green product selectivity of photocatalytic NO oxidation by the WO/g-CN composite is due to the separation and acceleration of the photogenerated charges of the WO/g-CN S-scheme heterojunction.