Synthesis Of CoP/WS₂ And CoP/MoS₂ & Performance In Electrochemical Hydrogen Evolution

Hydrogen is a clean and efficient energy carrier.Hydrogen evolution reaction through water electrolysis is one of the effective methods to produce hydrogen.A key factor of hydrogen production is to find earth abundant and efficient catalysts.Herein,we combined abundant CoP nanoparticles with transition metal disulfides concluding WS₂ and MoS₂,to prepare non-noble metal catalysts of high performance on catalyzing electrical activity of hydrogen evolution.Our main results of this thesis are shown below:?1?In the first part,we synthesized CoP nanoparticles.We found that CoP with sizes of¹0 nm are heavily agglomerate.Electrochemical testing results show that CoP has a low onset overpotiential of 80 mV.The Tafel slope and exchange current density of it is 86.26 mV/decade and 3.2×10^–5 A/cm² respectively.The stability test showed that the current density decreased obviously.We get the conclusion that CoP nanoparticles has good electrochemical catalytic activity but the stability is not good.?2?In the second part,we prepared CoP/WS₂ composites.The TEM images show that CoP nanoparticles combined with WS₂ nanosheet tightly.The electrochemical test show that after being combined with WS₂,the catalytic activity of CoP was improved.CoP/WS₂ composite with the ratio of 3:2 has the lowest overpotential of 50 mV.The Tafel slope and exchange current density of it is 64.63 mV/decade and 4.9×10^–5 A/cm²,respectively.These test results demonstrate the composite has good electrochemical catalytic activity.Finally,the stability test also shows that CoP/WS₂–3 has good electrochemical catalytic stability with minor current variations.?3?In our third part,CoP/MoS₂ composites were prepared to further explore the effect of other transition metal disulfides.From the electrochemical test results,we found the composite with a ratio of 4:1 has lower overpotential,smaller Tafel slope and bigger exchange current density than CoP or MoS₂ alone.The stability test was conducted and shows that the current density has a little decrease.These show that the composite has good electrochemical catalytic activity and better catalytic stability than CoP NPs,just as the CoP/WS₂-3 composite.