Combining SnO2-x and g-C3N4 nanosheets toward S-scheme heterojunction for high selectivity into green products of NO degradation reaction under visible light

Abstract NOx emissions cause many negative impacts on the living environment. The photocatalysis of semiconductors is superior for nitric oxide (NO) degradation due to their low redox potential. In this report, we combine SnO2-x/g-C3N4 heterojunction photocatalyst toward the high selectivity into green products under visible light illumination. Results show that SnO2-x/g-C3N4 heterojunction degraded 40.8% of NO, which is 1.6 times higher than that of g-C3N4. In addition, the selectivity coefficient of SnO2-x/g-C3N4 is higher 3 times than both pure SnO2-x and g-C3N4. Furthermore, SnO2-x/g-C3N4 expresses a superior stability for NO photocatalytic-degradation after five cycles. The scavenger trapping test results, and electron spin resonance (ESR) analysis also provide more understanding of the charge transfer mechanism of materials. SnO2-x/g-C3N4 heterojunction shows a high removal efficiency of NO gas, making it an up-and-coming environmental treatment candidate.