Highly efficient photocatalytic HO generation over dysprosium oxide-integrated g-CN nanosheets with nitrogen deficiency.

The increasing global crisis considers energy as the fundamental cause to conduct extensive research work to find clean alternative methods with high capabilities such as HO synthesis. Photocatalytic HO production can tackle this growing issue by maintaining environmental remediation. In this work, dysprosium oxide (Dy-oxide)-integrated g-CN has been synthesized and characterized with XRD, SEM, TEM, XPS, EPR, DRS, PL, and electrochemical analyses. Simulated solar light irradiation implemented photocatalytic HO production using the as-prepared catalysts. The facile preparation technique in the Ar atmosphere raises more N deficiency in the g-CN matrix. N-deficient g-CN nanosheets with an exceptionally high photocatalytic performance can be further enhanced by integrating well-dispersed Dysprosium oxide (DyO) particles onto g-CN. This study reports bandgap narrowing and various surface defects on g-CN with trace amounts of DyO. Undoped g-CN (Dy0) yielded 20.27 mM⋅g⋅h, while the optimized photocatalyst Dy15 showed high performance of HO production up to 48.36 mM⋅g⋅h. It is approximately 2.4 times higher than the pristine g-CN. Dy15 proves the positive impact of Dy-oxide on enhancing the N-deficient g-CN performance towards photocatalytic HO production. This work highlights the oxygen reduction reaction (ORR) through a mixed pathway of well-known two-step one-electron and one-step two-electron processes in HO generation.