A novel carbon-fiber geopolymer composite-coated electrodes for photoelectrocatalysis: Fabrication and application

The photoelectrocatalysis is an efficient and sustainable degradation method for organic contaminant, where the photoanode material plays a critical role. Development of novel, inexpensive, and high-performance photoanode materials is significant to enhance the degradation performance of anodes catalysis. Herein, a novel carbon-fiber geopolymer composite-coated electrode with low cost and facile production was prepared by incorporating carbon fibers in a geopolymer matrix. The as-developed photoelectrocatalyst coupled with persulfate could effectively degrade more than 98 % of rhodamine B within 6 min, which demonstrated superior catalytic activity compared with various catalysts reported in the literature. Moreover, the composite electrodes exhibited excellent reusability. The endogenous Fe2O3 and TiO2 in the geopolymer matrix were the main active materials, providing photoelectron-hole pairs for dye molecule degradation. Significantly, the carbon fibers in the matrix effectively connected the scattered oxide species and prompted the separation and migration of photoinduced carriers while enhancing the stability of the catalysts and improving the conductivity of the matrix. When the carbon content was increased from 0 to 6 wt%, the conductivity of the composite increased by 17.75 times. This study offers a cost-effective and eco-friendly photoelectrocatalyst, which shows significant potential for further development.