Co-Doped MoS 2 @TiO 2 Self-supported Nanoarray Photoelectrodes for Synergistically Enhance Photoelectrochemical Hydrogen Evolution

Abstract

The development of photoelectrochemical (PEC) water-splitting systems offers a viable technology for sustainable hydrogen production, contributing to addressing global energy needs. Herein, the Co-doped MoS2@TiO2 self-supported nanoarray photoelectrode is developed which exhibits a high photoelectrochemical hydrogen evolution rate of 41.67 μmol h⁻¹ cm⁻² which is 7.8 and 1.47 times higher than that of pristine TiO2 nanoarray and MoS2@TiO2 nanoarray. The synergistic enhancement in hydrogen evolution is attributed to the extended visible-light absorption, enhanced charge separation, and optimized hydrogen adsorption free energy.With the growing urgency to tackle the energy crisis and climate change, various sectors are constantly delving deeper into the exploration of green energy and sustainable alternatives to traditional fuels. [1][2][3] Hydrogen, as a clean and sustainable energy source, offers a pivotal solution for displacing fossil fuels. 4,5 Due to its ability to directly convert solar energy into chemical fuel with high efficiency and low environmental impact, photoelectrochemical (PEC) water splitting emerges as a promising green technology that leverages ubiquitous solar energy and water resources for sustainable hydrogen production. 6,7 In a typical PEC process, water molecules are dissociated into hydrogen and oxygen through photo-driven redox reactions on semiconductor-based photoelectrodes. Consequently, contemporary research endeavours in PEC water splitting have been predominantly focused on the advancement and refinement of photoelectrode materials. Since Fujishima et al. found that TiO2 can serve as a photoelectrode for H2 evolution under irradiation by simulated sunlight, TiO2 has attracted considerable research interest in the field of Photoelectrochemical due to its high chemical stability, low cost, and appropriate band gap structure. 8 However, The PEC