Vertically Aligned Oxygenated-CoS2–MoS2 Heteronanosheet Architecture from Polyoxometalate for Efficient and Stable Overall Water Splitting

• Published in: ACS catalysis Vol. 8; no. 5; pp. 4612 - 4621
• Main Authors: Hou, Jungang, Zhang, Bo, Li, Zhuwei, Cao, Shuyan, Sun, Yiqing, Wu, Yunzhen, Gao, Zhanming, Sun, Licheng
• Format: Journal Article
• Language: English
• Published: American Chemical Society 04.05.2018
• Subjects: electrocatalysts; heteronanosheets; overall water splitting; oxygenated CoS2-MoS2; polyoxometalates; heteronanosheets; electrocatalysts; oxygenated CoS2−MoS2; polyoxometalates; overall water splitting
• ISSN: 2155-5435; 2155-5435
• DOI: 10.1021/acscatal.8b00668

To achieve efficient conversion of renewable energy sources through water splitting, low-cost, earth-abundant, and robust electrocatalysts for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) are required. Herein, vertically aligned oxygenated-CoS2–MoS2 (O-CoMoS) heteronanosheets grown on flexible carbon fiber cloth as bifunctional electrocatalysts have been produced by use of the Anderson-type (NH4)4[CoIIMo6O24H6]·6H2O polyoxometalate as bimetal precursor. In comparison to different O-FeMoS, O-NiMoS, and MoS2 nanosheet arrays, the O-CoMoS heteronanosheet array exhibited low overpotentials of 97 and 272 mV to reach a current density of 10 mA cm–2 in alkaline solution for the HER and OER, respectively. Assembled as an electrolyzer for overall water splitting, O-CoMoS heteronanosheets as both the anode and cathode deliver a current density of 10 mA cm–2 at a quite low cell voltage of 1.6 V. This O-CoMoS architecture is highly advantageous for a disordered structure, exposure of active heterointerfaces, a “highway” of charge transport on two-dimensional conductive channels, and abundant active catalytic sites from the synergistic effect of the heterostructures, accomplishing a dramatically enhanced performance for the OER, HER, and overall water splitting. This work represents a feasible strategy to explore efficient and stable bifunctional bimetal sulfide electrocatalysts for renewable energy applications.