Solar-driven bio-electro-chemical system for synergistic hydrogen evolution and pollutant elimination simultaneously over defect-rich CoN–MoS2/biomass nanosheets

• Published in: Journal of power sources 2020-12, Vol.478, p.228755, Article 228755
• Main Authors: Zeng, Libin, Li, Xinyong, Fan, Shiying, Yin, Zhifan, Mu, Jincheng, Qin, Meichun, Chen, Aicheng
• Format: Article
• Language: English
• Subjects: Defect-rich; Dual-doping; Photo-bio-electrocatalytic; Synergistic effect
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2020.228755

We describe the successful fabrication of a superior Co and N heteroatom dual-doped MoS2 anchored on porous biomass carbon (PBC) with the formation of interfacial Mo–Co/N active centers. Originating from its exposure of multiple metal oxidation states as well as special PBC framework, this hybrid catalyst exhibits admirable electrocatalytic activity for the hydrogen evolution reaction (HER) and synchronous antibiotic degradation in a photo-driven double cathode microbial fuel cell (DC-MFC), which demonstrates remarkable synergistic catalytic effects in contrast to a single cathode MFC (SC-MFC). Subsequently, a comprehensive characterization analysis combining with density functional theory (DFT) calculations further elucidates that the incorporation of N and Co atoms could facilitate the elevation of the conduction band (−0.12 eV to −1.02 eV) by refining the intrinsic defect band structure. On one hand, the self-generation of higher redox potential sulfate radicals (SO4-) largely accelerates the mineralization of the target pollutant, and the corresponding degradation pathway is investigated. On the other hand, the creation of interstitial sulfur vacancies and interfacial Co–Mo–S sites are beneficial to enhancing its catalytic activity for H2 evolution and pollutant elimination. Therefore, we confirm that these heteroatom-incorporated MoS2 based bio-functional electrodes are promising candidates for energy conversion and environmental remediation applications. Co–N@MoS2/carbon catalyst with more active sites is synthesized and shows a longer lifetime of photo-excited electrons, which makes it excellent photoelectrocatalytic performance for hydrogen evolution and antibiotic degradation synchronously in the dual-cathode bio-electrocatalytic system. [Display omitted] •Defect-rich Co–N dual-doping MoS2/PBC electrocatalyst was synthesized.•Simultaneously improving the pollutant mineralization and hydrogen evolution.•In situ self-generating sulfate radicals in the photo-driven DC-MFC system.