1T phase MoS2(1T-MoS2)is a promising substitute of platinum electrocatalyst for hydrogen evolution reaction(HER)due to its high intrinsic activity but suffering from thermodynamical instability.Although great efforts have been made to synthesize 1T-MoS2 and enhance its stability,it remains a big challenge to realize the phase control and stabilization of 1T-MoS2.Herein,based on crystal field the-ory analysis,we propose a new solution by designing an electrocatalyst of 1T-MoS2 nanosheets anchoring on black TiO2-x nanotube arrays in-situ grown on Ti plate(1T-MoS2/TiO2-x@Ti).The black TiO2-x sub-strate is expected to play as electron donors to increase the charge in Mo 4d orbits of 1T-MoS2 and thus weaken the asymmetric occupation of electrons in the Mo 4d orbits.Experimental results demonstrate that black TiO2-x nanotubes shift electrons to MoS2 and induce MoS2 to generate more 1T phase due to stabilizing the 1T-MoS2 nanosheets compared with a Ti substrate.Thus 1T-MoS2/TiO2-x@Ti shows much improved HER performance with a small Tafel slope of 42 mV dec-1 and excellent catalytic stability with negligible degradation for 24 h.Theoretical calculations confirm that the black TiO2-x substrate can effectively stabilize metastable 1T-MoS2 due to electrons transferring from black TiO2-x to Mo 4d orbits.This work sheds light on the instability of 1T-MoS2 and provides an essential method to stabilize and effi-ciently utilize 1T-MoS2 for HER.

Ting Zhang;Tingxuan Yang;Guoxing Qu;Saifang Huang;Peng Cao;Wei Gao

Department of Chemical and Materials Engineering,the University of Auckland,Private Bag 92019,Auckland 1142,New Zealand;School of Material Science and Engineering,Nanchang University,Nanchang 330031,Jiangxi,China;School of Materials Science and Engineering,Jiangsu University of Science and Technology,Jiangsu 212003,Zhenjiang,China

能源化学

[1]Ting Zhang;Tingxuan Yang;Guoxing Qu;Saifang Huang;Peng Cao;Wei Gao-.Phase control and stabilization of 1T-MoS2 via black TiO2-x nanotube arrays supporting for electrocatalytic hydrogen evolution)[J].能源化学,2022(05):71-77

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