Research On Microbial Fuel Cell Anode Optimization And Its Application Of Hydrogen Production

Microbial fuel cells are a novel bio-electrochemical technology for directly conversing biodegradable substrates into electricity,based on the bio-catalysis of electrochemically active bacteria.MFC technology has many applications in the fields of pollutant remediation,hydrogen production and biosensors.In the previous two decades,significant developments and achievements have made MFC output power density increased greatly.However,anode is still a limiting factor for enhancing the performance of dual-chamber MFCs due to the slow costly electrode materials and microbial kinetics.Molybdenum disulfide（MoS₂）nanoflowers and heat-treatment method were employed to modify the low-cost stainless steel fiber felt（SSFF）base-anode.Polyaniline（PANI）electrochemically modified SSFF cathode was used to study the performance of MEC hydrogen generation.The main work are summarized as follows:（1）One-step hydrothermal method for synthesizing MoS₂ nanoflowers and its application in MFC anode modification.MoS₂ nanoflower was synthesized via a convenient one-step hydrothermal method.MoS₂ was used to modify carbon cloth（CC）and SSFF anode to obtain MoS₂-CC and MoS₂-SSFF,and their performances were compared separately.The results showed that the maximum power density of MoS₂-CC(960.4 mW·m^-2)and MoS₂-SSFF(713.6 mW·m^-2)was 1.7 times and 3.6times than that of the unmodified counterparts,respectively.（2）MFC anode performance of heat-treated-SSFFs.Heat treatment method was employed to oxidize SSFF,and its performance was compared with untreated-SSFF,multi-walled carbon nanotube modified SSFF（MW-CNT-SSFF）and carboxyl graphene modified SSFF（CG-SSFF）.The results showed that electrode redox performance of heat-treated-SSFF was enhanced.X-ray photoelectron spectroscopy test（XPS）indicated that the content of iron oxides on the heat-treated-SSFF significantly increased,and the biocompatibility of MFC was also improved significantly.The MFC maximum power density of heat-treated-SSFF(2324 mW·m^-2)was 11.8 times,3.35 times and 72%than that of untreated-SSFF,MW-CNT-SSFF and CG-SSFF,respectively.（3）Microbial electrolysis cells（MECs）for hydrogen production.Based on the CC bio-anode of MFC,it was then run as an MEC for hydrogen production.PANI was electrochemically polymerized on SSFF by CV technology.The cycle of electrochemical polymerization（15,20,and 25）was selected.The hydrogen production rate of the selected PANI₂₀SSFF-cathode（20）was 0.5 m³·m^-3·d^-1.The results showed that PANI₂₀SSFF-cathode modified by CV technology can be effectively used in MEC simultaneously on wastewater treatment and hydrogen energy recovery.