High-efficient photocatalytic fuel cell integrated with periodate activation for electricity production by degradation of refractory organics

摘要

In this work, a novel photocatalytic fuel cell integrated with a periodate activation process was used for the degradation of pollutants and synchronous generation of electricity. This designed system is comprised of reduced graphene oxide/TiO2 nanotubes photoanode and polypyrrole/multi-walled carbon nanotube cathode. Herein, a synergistic procedure was presented by introducing periodate in the photo fuel cell system. Compared to the periodate activation process and single photo fuel cell, the combined system displayed better performance. The addition of periodate to the photo fuel cell system extended the radical reactions from the surface of electrodes to the entire solution. Meanwhile, periodate as an electron acceptor efficiently suppressed the recombination of electron/hole pairs. Hence, the photo fuel cell/periodate system significantly increased the degradation efficiency by 54% and electricity generation by 87% relative to the single photo fuel cell. The highest degradation efficiency of 99% and maximum power density of 1500 mu W cm(-2) were obtained using citric acid as the organic compound. The practical factors, including initial pH, periodate concentration, and organic compound concentration, were optimized. The radical quenching tests revealed that HO center dot, singlet oxygen, IO4 center dot, IO3 center dot, O-center dot(2)-, and holes played important roles in the degradation process.