Dual-Functional Photo(electro)catalytic Systems for Sustainable Wastewater Treatment and Energy Production: Opportunities and Challenges

Dual-Functional Photo(electro)catalytic Systems for Sustainable Wastewater Treatment and Energy Production: Opportunities and Challenges

Performance metrics reveal that photocatalytic systems outperform photo-electrocatalytic methods for wastewater treatment and hydrogen production. While suspended photocatalyst particles are widely studied, photo-electrocatalytic systems remain less explored. This is partly due to challenges in catalyst recovery and optimizing redox reaction parameters in single-phase systems, hindering their large-scale feasibility.

Dual-functional photo-electrocatalytic systems offer a promising alternative. By separating oxidation and reduction reactions in different chambers, these systems minimize recombination losses and simplify semiconductor photoelectrode separation post-reaction. However, several key aspects require further investigation:

1. Cathode Electrocatalyst Selection: Current options are limited, demanding extensive research into cost-effective and stable cathode materials for PEC systems.

2. End-Product/Intermediate Analysis: Future research should prioritize analyzing the end-products and intermediates generated from organic pollutant degradation.

3. Scaling Up from the Lab: Most studies on simultaneous hydrogen energy generation and wastewater treatment using dual-functional systems are confined to laboratory settings, employing one or two organic contaminants. Large-scale or pilot-scale studies with real wastewater are scarce, limiting the understanding of real-world applications.

Addressing these challenges will be crucial in unlocking the full potential of dual-functional photo-electrocatalytic systems for sustainable wastewater treatment and clean energy production.