Enhancements in PEC water splitting for sustainable hydrogen production using Mn_xCo_0.015Zn_1-xO bifunctional photocatalyst

The widespread adoption of photoelectrochemical (PEC) water splitting to harvest clean hydrogen fuel is dependent on the development of effective photocatalysts. The present study aimed to synthesize Mn and Co co-doped ZnO (MCZO) photocatalysts and thoroughly investigate their structural, optical, and PEC properties. Compared to Co-doped ZnO (CZO), the incorporation of Mn dopants increased light absorption, reduced charge carrier recombination, and altered the optical and electrical properties of the MCZO material. Throughout the oxygen evolution reaction, the MCZO electrode outperformed the CZO electrode by a factor of 2.5, leading to a peak photocurrent density of 2.9 μA/cm². During the hydrogen evolution reaction (HER), the MCZO photocathode produced a photocurrent density of 14 μA/cm², which was approximately six times higher than that of the CZO photocathode. The substantial spike in HER activity highlights the advantages of co-doping Mn and Co in ZnO even more. Through long-term stability testing, the MCZO electrode's resilience to continuous PEC operation was assessed. The results demonstrated very good stability, with the photocurrent density remaining relatively constant over time indicating its potential as a dual-purpose photocatalyst for the environmentally friendly and efficient production of hydrogen through PEC water splitting.