Efficient H2 production in a microbial photoelectrochemical cell with a composite Cu2O/NiOx photocathode under visible light. (15th April 2016)

• Record Type: Journal Article
• Authors: Liang, Dawei; Han, Guodong; Zhang, Yongjia; Rao, Siyuan; Lu, Shanfu; Wang, Haining; Xiang, Yan
• Is Part Of: Applied energy. Volume 168(2016)
• Page Start: 544
• Page End: 549
• Publication Date: 2016-04-15
• Subjects: Microbial photoelectrochemical cell -- Cu2O -- NiOx -- H2 production; Power (Mechanics) -- Periodicals; Energy conservation -- Periodicals; Energy conversion -- Periodicals; 621.042
• DOI: 10.1016/j.apenergy.2016.01.118
• Languages: English
• ISSNs: 0306-2619

Abstract

Highlights: A MPEC was constructed for wastewater treatment and energy recovery. Hydrogen generation was achieved by MPEC under visible light illumination. The photocathode in MPEC was prepared by a p-Cu2 O/NiO x composite electrode. Effect of NiO x and external bias on photocurrent and H2 generation were investigated. Abstract: Microbial photoelectrochemical cells (MPEC) is a state-of-the-art and self-sustained 'waste-to-energy' solution through coupling a synergistic microbial conversion of waste organics into electron and proton in a bioanode and photoelectrochemical catalysis of proton reduction for hydrogen evolution in a photocathode. With the advantage of visible light adsorption, p -type semiconductor Cu2 O has exhibited superior photocatalytic potential for hydrogen evolution reaction (HER), but the instability of p -type Cu2 O hinders its further practical application. Here, we fabricated a Cu2 O/NiO x composite photocathode by spin coating a thin film of NiO x on Cu2 O photocathode to improve its stability and photocurrent. Results showed that NiO x layer on Cu2 O had a trade-off effect on photocathode performance. The thicker of NiO x film on Cu2 O, the lower of the photocurrent, but more stable of the Cu2 O electrode. With an optimal 240 nm thickness of NiO x layer, the Cu2 O/NiO x composite photocathode extracted excited electrons effectively, and a H2 production rate of 5.09 μL h −1 cm −2 was obtained from a MPEC under continuous light illumination with 0.2 V external bias. By tuning the synergistic effect of bioanode and photocathode, MPEC could provide a feasible solution on simultaneously organic conversion and energy restoration from wastewater and solar light.