Abstract:
This study mainly highlights the feasibility of treated wastewater in photo and
electrocatalytic processes, advancing sustainable hydrogen generation technologies.
Photocatalytic hydrogen production from treated wastewater tackles energy and water
scarcity issues, advancing renewable technology and optimizing resource management.
Cerium oxide (CeO2) has shown promising photocatalytic activity but is limited by high
carrier recombination rates and a wide bandgap. To address these constraints, varying
levels of samarium doping was employed to enhance the photocatalytic performance of
cerium oxide. In this work, SmxCe1-xO2 (x = 0, 2, 4, 6%) with oxygen vacancy defects was synthesized through a simple sol-gel combustion method. The 2% samarium doped cerium oxide, with increased oxygen vacancies and a reduced bandgap, showed enhanced photocatalytic activity for hydrogen production and dye degradation, achieving 96.2% dye degradation for toluidine blue and 71.9% for crystal violet. This treated wastewater was then employed for hydrogen production and the maximum hydrogen production efficiency was 4304 μmol h⁻¹ g⁻¹ with a 44.7% Apparent Quantum Efficiency (AQE). Further, investigations with nickel foam assessed the potential of treated wastewater in electrocatalysis, revealing HER and OER overpotentials of 168 mV and 386 mV respectively
