Identification of few-layer ReS2 as photo-electro integrated catalyst for hydrogen evolution

• Published in: Nano energy 2018-06, Vol.48, p.337-344
• Main Authors: Xu, Xiaoyong, Zhao, Heng, Wang, Rui, Zhang, Zehui, Dong, Xuefeng, Pan, Jing, Hu, Jingguo, Zeng, Haibo
• Format: Article
• Language: English
• Subjects: Function coupling; PEC cells; Rhenium disulfide (ReS2); Water splitting
• ISSN: 2211-2855
• DOI: 10.1016/j.nanoen.2018.03.078

Efficient water splitting via photo-electrocatalytic (PEC) systems holds great promise for producing hydrogen fuel in future energy devices. The artificial integration of photosensitive semiconductors and co-catalysts into effective PEC electrodes is becoming significantly challenging. Here, few-layer ReS2 nanosheets (NSs) were found to have both favorable solar light harvesting and proton reducing kinetics based on the assessments for electronic band structure and Gibbs free energy (ΔGH*) of hydrogen adsorption. Furthermore, the naturally coupling between optical and catalytic functions was demonstrated using ReS2 NSs grown on conductive carbon fiber clothes (CFC) as a hydrogen evolution reaction (HER) cathode, where the simulated 1 sun irradiation (100 mW cm−2) could significantly improve the catalytic activity along with anodic shifts of ca. 37 mV in onset potential and ca. 39 mV in over potential, and near 3-fold increase in exchange current density. The comparative analyses on Tafel, turnover and active sites revealed that the light-improved HER performance was due to the photo-generated hot electron injection into edge active sites. This work identifies ReS2 as a naturally PEC function-coupling material, opening a prospect of utilizing light-activated catalysts or co-catalysts to integrate catalysis with solar energy in PEC systems. The photo-induced hot electron injection into HER enables the naturally coupling of photoelectric response and catalytic kinetics in a unique TMD ReS2 for hydrogen production. [Display omitted] •Few-layer ReS2 was assessed on electronic band and ΔGH* for PEC HER property.•Few-layer ReS2 was identified to integrate the light harvesting and HER kinetics.•PEC function coupling was demonstrated in a 3D ReS2@CFC cathode for HER.