Solar promoted azo dye degradation and energy production in the bio-photoelectrochemical system with a g-C3N4/BiOBr heterojunction photocathode

JOURNAL OF POWER SOURCES

卷:371

Article

Hou, Yanping¹  Gan, Yuanyuan¹  Yu, Zebin¹  Chen, Xixi¹  Qian, Lun¹  Zhang, Boge¹  Huang, Lirong¹  Huang, Jun¹ 

[1] Guangxi Univ, Guangxi Coll & Univ Key Lab Environm Protect, Sch Resources Environm & Mat, Nanning 530004, Peoples R China

关键词: Bio-photoelectrochemical system;    g-C3N4/BiOBr heterojunction photocathode;    Azo dye degradation;    Hydrogen production;    Current generation;   

DOI  :  10.1016/j.jpowsour.2017.10.033

来源: Elsevier

【 摘 要 】

In this study, a single-chamber bio-photoelectrochemical system (BPES), integrating advantages of bioelectrochemical system and photocatalysis process, is developed using a g-C3N4/BiOBr heterojunction photocathode for methyl orange (MO) degradation and simultaneous energy recovery. Photocatalytic activities of g-C3N4/ BiOBr, g-C3N4 and BiOBr are characterized by UV-vis diffuse reflectance spectra (UV-vis DRS) and Photoluminescence (PL) spectra; and electrochemical activities of photocathodes are examined by linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS). Results show that with an applied voltage of 0.8 V and under simulated solar irradiation, MO decolorization with g-C3N4/BiOBr photocathode reaches 97.8% within 4 h, higher than those with g-C3N4 (85.3%) and BiOBr (87.3%) photocathodes. Likewise, higher hydrogen production rate (143.8 L m(-3)d(-1)) is observed using g-C3N4/BiOBr photocathode; while values for g-C3N4 and BiOBr photocathodes are 124.3 L m(-3)d(-1) and 117.1 L m(-3)d(-1), respectively. PL and EIS reveal that superior performance of g-C3N4/BiOBr photocathode can be attributed to more efficient separation of photo generated electron-hole pairs, lower resistance and better charge transfer. Synergistic effect occurs among biological, electrochemical and photocatalytic processes in illuminated BPES for MO removal. Photocathode optimization and system stability evaluation are conducted. This study demonstrates that the BPES holds great potential for efficient refractory organics degradation and energy production.

【 授权许可】

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