A novel airlift photocatalytic fuel cell (APFC) with immobilized CdS coated zerovalent iron (Fe@CdS) and g-C3N4 photocatalysts film as photoanode for power generation and organics degradation

Abstract

In this work, a novel design of external loop airlift photocatalytic fuel cell (APFC) was proposed. CdS coated zerovalent iron (Fe@CdS) and g-C3N4 nanocatalysts (in the ratio of 1:1) immobilized on a polystyrene film was fabricated as photoanode and incorporated in the APFC under UV irradiation. The fabricated polystyrene film photoanode was fixed inside the inner surface of external tube (downcomer) while rGO/carbon brush was used as aerated cathode fixed in the riser section. Phenol was used as substrate to study the performance of APFC and different operating conditions including air flowrate, initial substrate concentration and electrolyte concentration have been studied. The proposed design of APFC displayed outstanding results in term of power generation and wastewater treatment. The maximum power density (Pmax), open circuit voltage (Voc) and short circuit current density (Jsc) were respectively 1.57 mW/cm2, 1.19 V and 2.525 mA/cm2 at specific conditions (air flowrate = 200 mL/min, initial phenol concentration = 100 mg/l and electrolyte concentration = 0.2 M). Furthermore, the APFC exhibited 95.3 % phenol photoelectrocatalytic degradation 91.0 % and TOC reduction compared with 79.4 % of simple photocatalytic degradation and 62.3 % TOC reduction within 120 min. The immobilized binary photocatalyst film was effectively recycled five times. The good self-mixing and thus, speed up the mass transport in the proposed unique design of APFC helps to enhance the output performance of the APFC so making it appropriate design for large scale PFCs.