Nanomaterial enhanced photoelectrocatalysis and photocatalysis for chemical oxygen demand sensing a comprehensive review

Abstract

Chemical oxygen demand-COD is essential for water pollution control and monitoring and is also used to validate wastewater treatment technologies. Conventional COD determination use of costly toxic inputs that do not align with Sustainable Development Goals 6. To address these environmental challenges, photocatalytic (PC)- and photoelectrocatalytic (PEC)-COD sensors have emerged as a solution. This comprehensive review examines PC-COD and PEC-COD sensors in terms of nanomaterials used and their properties, focusing on how multiple variables influence PC activity and sensor performance. Analytical principles and operational variables affecting performance in COD determination are discussed. Finally, a series of materials and conditions are proposed to improve the viability of PEC-COD sensors currently and in the future.