Study On The Organic Solution Synthesis And Electrocatalytic Hydrogen Evolution Properties Of MoSe₂-Ni₃Se₄ Nanocomposites

As a kind of environmentally friendly and sustainable approach to energy,hydrogen evolution reaction(HER)has gained comprehensive attention.Design and preparation of low-cost and high-efficiency HER catalysts is the key to put this technology into extensive uses.As a kind of typical transition metal sulfide electrocatalyst,MoSe2 possesses good HER performance.But as a kind of semiconductor,it has poor electroconductivity which can't satisfy the needs of HER.Single component catalysts also don't exhibit high catalytic activity for all the intermediate reactions such as the adsorption and desorption of hydrogen in the whole HER.Hence a series of MoSe2-Ni3Se4 nanocomposites with dirrenent structures and component ratios were synthesized by organic solution methods on the aspects to improve conductivity of the catalysts and take advantage of synergistic effect between different catalysts.And then HER performances of the materials were tested.The main contents and conclusions of this thesis are as follows:1.Se powder,Ni(acac)2 and Mo(CO)6 wew used as Se,Ni and Mo sources respectively.Octadecene(ODE)was used as organic solvent,and oleice acid(OA)was used as organic solvent and surfactant.Using organic solution method,we achieved lamellar Ni3Se4 growth on the MOSe2 nano flowers' surface,and then obtained the MoSe2-Ni3Se4 nanohybrids.By adjusting the ration of Ni/Mo,we can regulate the components and morphology structure of the nanohybrids.Combined with exploration of the ways to inject Ni sources,the growth mechanism of Ni3Se4 on the surface of MoSe2 nanoflowers was proposed.Electrochemical testing revealed that when the ration of Ni/Mo was 1/2(Mo2Nil),the material had the best HER performance.The oneset overpotential for Mo2Nil sample was 140 mV and when cathode current density reached 10 mA cm-2,it required the smallest overpotential of 203 mV,which was 31 mV smaller than pure MoSe2.The corresponding Talfel slope was only 57 mV s-1.2.Through the use of low-activity ODE-Se as Se source to selenize the Ni source solely,and using OA as surfactant to control the growth of Ni3Se4 we obtained nanohybrids in which Ni3Se4 particles adhered to the surface of MoSe2 nanoflowers and the ration of Ni/Mo in the nanohybirds was still 1/2(Mo2Ni1(P)).According to the electrochemical test,we found that compared with pure MoSe2,Mo2Ni1(P)sample possessed a little better HER performance,which indicated that different structures in the composite materials could also influence the HER performance.