Photocatalytic H2 Generation and Cr(VI) Reduction by p-n Heterojunction of CuO/Nanostructured Nitrogen-Enriched Carbon Nitrides

The construction of p-n heterojunction is one of the efficient ways to promote photocatalytic activities. Here in, different weight percentages of CuO/g-C3N5 are constructed by sol-gel approach (i.e., 10 CCN, 30 CCN, 50 CCN) for visible-light-driven photocatalytic water-splitting to produce hydrogen as well as Cr(VI) reduction. The structural, morphological, and electronic properties of the photocatalyst have been characterized through various physicochemical techniques. We have shown that the p-n heterojunction of CuO/g-C3N5 i.e. 30 CCN exhibited enhanced production of H2 (37.4 µmol in 4 h) as compared to other photocatalysts. Moreover, 30 CCN exhibited better Cr(VI) photo-reduction of 92% in 180 min under visible light irradiation. The excellent photocatalytic behaviour towards water splitting reactions is attributed to the extended visible light absorption due to redshift and electron-hole charge separation due to p-n heterojunction resulting in total electronic integration. This work demonstrates the facile synthesis of CuO/g-C3N5 toward water splitting reactions to produce hydrogen and Cr(VI) reduction for energy production and environmental abetment in a clean, green, simple and cost-effective manner.