Activate Fe3S4 Nanorods by Ni Doping for Efficient Dye-Sensitized Photocatalytic Hydrogen Production

Developing suitable catalysts capable of receiving injected electrons and possessing active sites for hydrogen evolution reaction (HER) is the key to building an efficient dye-sensitized system for hydrogen production. Fe3S4 is generally regarded as an inferior HER catalyst among the metal sulfide family, mainly due to its weak surface adsorption toward H atoms. In this work, we demonstrate a facile metal-organic framework-derived method to synthesize uniform Fe3S4 nanorods and active them for HER by Ni doping. Our experimental results and theoretical calculations reveal that Ni doping can greatly modify the electronic structure of Fe3S4 nanorods, improving their electron conductivity and optimizing their surface adsorption energy toward H atoms. Sensitized by a commercial organic dye (eosin-Y), 1%Ni-doped Fe3S4 nanorods display a high H-2 production rate of 3240 mu mol g(cat)(-1) h(-1) with an apparent quantum yield of 12% under 500 nm wavelength, which is significantly higher than that of pristine Fe3S4 and even higher than that of 1% Pt-deposited Fe3S4. The working mechanism of this dye-sensitized system is explored, and the effect of Ni-doping concentration has been studied. This work presents a facile strategy to synthesize metal-doped sulfide nanocatalysts with greatly enhanced activity toward photocatalytic H-2 production.

Automated summary

This study presents a facile method to synthesize uniform Fe3S4 nanorods with enhanced HER activity through Ni doping. Sensitized by a commercial organic dye, the 1%Ni-doped Fe3S4 nanorods exhibit significantly higher H-2 production rate and apparent quantum yield compared to pristine Fe3S4 and even 1% Pt-deposited Fe3S4. The working mechanism of this dye-sensitized system and the effect of Ni-doping concentration have been explored.