Photo-driven bioelectrochemical photocathode with polydopamine-coated TiO2 nanotubes for self-sustaining MoS2 synthesis to facilitate hydrogen evolution

Abstract Developing low-energy and high-efficiency photoelectrocatalysts towards hydrogen evolution reaction is one of the frontier technologies capturing intensive research enthusiasm. In this work, a sustainable solar-driven microbial fuel cell is successfully constructed to synthesize rich edge sites of MoS 2 nanomaterials and in situ utilize dual electrons mode for hydrogen generation under visible light illumination (>420 nm). For this photo-driven coupling system, the continuous formation of MoS 2 catalyst is more beneficial for efficient hydrogen generation without external bias assistance. Such unique preparation method endows the system to possess more active edge sites for MoS 2 exposure, and promotes the obtained materials to exhibit super-hydrophilic behavior. Additionally, the introduction of MoS 2 semiconductor could cooperate with bio-electrons to dramatically hinder the recombination of photo-excited electron-hole pairs, leaving more opportunities for photo-electrons to participate hydrogen evolution reaction under the bioelectric field. Simultaneously, the constructed MoS 2 based electrode performs excellent photoelectrochemical performance (the onset overpotential only ∼36 mV vs. SHE, Tafel slope of 53 mV per decade) and hydrogen evolution activities for hydrogen production with 0.003 m 3  m −3 min −1 rate. This work not only leads to a promising approach for the preparation of high efficient photoelectrocatalysts, but also highlights the potential strategy for diverse applications.