1-D semiconducting TiO2 nanotubes supported efficient bimetallic Co-Ni cathode catalysts for power generation in single-chambered air-breathing microbial fuel cells

Herein, the synthesis and electrocatalytic behaviour of cobalt (Co) and nickel (Ni) nanocatalysts supported on TiO2-nanotubes towards oxygen reduction reaction (ORR) in single-chambered MFCs are reported. A study of various weight ratios of cobalt–nickel nanoparticles on TiO2 nanotube support is performed to find the activity of the catalyst, and it is observed that the catalyst T1 (Co-Ni (1:1) / TiO2-NTs) is the best one compared to the other synthesized catalysts. The results of the electrochemical study of these catalysts indicate that the catalyst T1 (reduction potential at 560 mV with −0.257 mA current) shows higher stability and electrocatalytic activities in comparison to Pt/C catalyst (reduction potential at 509 mV with −0.235 mA current) towards ORR. T1 catalyst demonstrates an enhanced catalytic activity in MFCs with a maximum power output of ∼104 mW/m2 compared to 64 mW/m2 for Pt/C. The excellent electrocatalytic performance of T1 catalyst is attributed to the enhanced rate of ORR, conductivity, and stability of the catalyst. The experimental results demonstrate the application of TiO2-NTs as an advantageous support material in the construction of affordable and productive cathode catalysts over conventional Pt/C catalyst in MFC.