Electrocatalyst for hydrogen evolution reaction

Abstract

The electrocatalyst for hydrogen evolution reaction includes nanosheets of molybdenum disulfide (MoS2) deposited on a carbon fiber substrate. The catalyst is formed in stepwise fashion by chemical vapor deposition of nanosheets of MoO3 onto the substrate, then reducing the MoO3 to nanosheets of MoO2 using sublimed sulfur, then by reaction of sulfur vapor with the MoO2 to form nanosheets of MoS2 on the carbon fiber substrate. The catalyst is multifaceted, having a large density of edges providing catalytically active sites for the hydrogen evolution reaction. The activity of the catalyst is enhanced by coating the catalyst with spherical fullerenes (nC60).

We claim: 
     
         1 . An electrocatalyst for hydrogen evolution reaction, comprising:
 a carbon fiber paper substrate; and   a plurality of nanosheets of MoS 2  on the carbon fiber substrate, the nanosheets having a plurality of catalytically active edge sites along basal planes thereof.   
     
     
         2 . The electrocatalyst for hydrogen evolution reaction according to  claim 1 , wherein the basal planes comprise faceted edges. 
     
     
         3 . The electrocatalyst for hydrogen evolution reaction according to  claim 2 , wherein the basal planes comprise collapsed edges. 
     
     
         4 . The electrocatalyst for hydrogen evolution reaction according to  claim 1 , wherein the nanosheets further comprise spherical fullerene nanoclusters. 
     
     
         5 . The electrocatalyst for hydrogen evolution reaction according to  claim 4 , wherein the spherical fullerene nanoclusters are about 7 μm in diameter. 
     
     
         6 . The electrocatalyst for hydrogen evolution reaction according to  claim 5 , wherein the spherical fullerene nanoclusters cover about 2% of the total surface area of carbon fibers of the carbon fiber paper substrate. 
     
     
         7 . The electrocatalyst for hydrogen evolution reaction according to  claim 1 , wherein the nanosheets are dispersed across an area of about 2 cm 2  of the carbon fiber paper substrate. 
     
     
         8 . A method of making an electrocatalyst for hydrogen evolution reaction, comprising the steps of:
 depositing nanosheets of MoO 3  onto a carbon fiber paper by chemical vapor deposition;   reducing the nanosheets of MoO 3  to nanosheets of MoO 2  by reaction with sublimed sulfur; and   sulfiding the nanosheets of MoO 2  to form nanosheets of MoS 2  integrated with the carbon fiber paper substrate, the nanosheets of MoS 2  integrated with the carbon fiber paper substrate providing the electrocatalyst for hydrogen evolution reaction.   
     
     
         9 . The method of making an electrocatalyst for hydrogen evolution reaction according to  claim 8 , wherein the nanosheets of MoO 3  deposited onto the carbon fiber paper are about 1-2 μm in lateral dimensions. 
     
     
         10 . The method of making an electrocatalyst for hydrogen evolution reaction according to  claim 8 , wherein the reaction with sublimed sulfur occurs at a temperature of about 400° C. 
     
     
         11 . The method of making an electrocatalyst for hydrogen evolution reaction according to  claim 8 , wherein the sulfiding of the nanosheets of MoO 2  occurs at a temperature of about 850° C. 
     
     
         12 . The method of making an electrocatalyst for hydrogen evolution reaction according to  claim 8 , wherein the nanosheets of MoS 2  comprise a plurality of catalytically active edge sites along basal planes thereof. 
     
     
         13 . The method of making an electrocatalyst for hydrogen evolution reaction according to  claim 8 , further comprising:
 immersing the nanosheets of MoS 2  integrated with the carbon fiber paper substrate in a solution of spherical fullerenes (nC 60 ); and   annealing the nanosheets of MoS 2  integrated with the carbon fiber paper substrate after immersion in the fullerenes.   
     
     
         14 . An electrocatalyst for hydrogen evolution reaction prepared according to the method of  claim 8 . 
     
     
         15 . A method of making an electrocatalyst for hydrogen evolution reaction, comprising the steps of:
 depositing nanosheets of MoO 3  onto carbon fiber paper by chemical vapor deposition;   reducing the nanosheets of MoO 3  to nanosheets of MoO 2  by reaction with sublimed sulfur;   sulfiding the nanosheets of MoO 2  to form nanosheets of MoS 2  integrated with the carbon fiber paper substrate, the nanosheets of MoS 2  integrated with the carbon fiber paper substrate providing the electrocatalyst for hydrogen evolution reaction;   immersing the nanosheets of MoS 2  integrated with the carbon fiber paper substrate in a solution of spherical fullerenes (nC 60 ); and   annealing the nanosheets of MoS 2  integrated with the carbon fiber paper substrate after immersion in the fullerenes.   
     
     
         16 . The method of making an electrocatalyst for hydrogen evolution reaction, according to  claim 15 , wherein the nanosheets of MoO 3  deposited onto the carbon fiber paper are about 1-2 μm in lateral dimensions. 
     
     
         17 . The method of making an electrocatalyst for hydrogen evolution reaction, according to  claim 15 , wherein the reaction with sublimed sulfur occurs at a temperature of about 400° C. 
     
     
         18 . The method of making an electrocatalyst for hydrogen evolution reaction according to  claim 15 , wherein the sulfiding of the nanosheets of MoO 2  occurs at a temperature of about 850° C. 
     
     
         19 . The method of making an electrocatalyst for hydrogen evolution reaction according to  claim 15 , wherein the nanosheets of MoS 2  comprise a plurality of catalytically active edge sites along basal planes thereof. 
     
     
         20 . An electrocatalyst for hydrogen evolution reaction prepared according to the method of  claim 15 .