The Research Of Cobalt Phosphide Nanomaterials With Different Morphology For Electrochemical Hydrogen Evolution Properties

A focus and concern on climate change and exhaustible fossil fuel hasgave rise to the need for clean and renewable energy sources and carrier.Hydrogen,as an energy carrier,has become more attractive because of it's gravimetric energy density is the highest of any known fuel,and is without CO₂ emissionsin the process of energy conversion.So far,most hydrogen for industrial use is made via steam reforming of methane or natural gas.The main reasons for this production technology dominates sources is that high availability and low price,but it's is not a renewable sources of energy and the problem of CO₂ release is hard solved.The interconversion between water and hydrogen is responsible for the environment,carbon-free alternative for hydrogen evolution.However the hydrogen evolution reaction is carried out,there are still difficulties without the use ofprecious metal catalysts.In order to solve this problem,theexploration of hydrogen evolution catalyst has become a hotspot of current research.Earlier research has found that Pt-based material is the best metal catalyst to electrolysis of water,but itsscarce and costly problems severely limit major commercial application as a catalyst.The research of acid-stable and low-price nonprecious metal has been the main way to slove the problem,but microbial electrolysis cell needs catalysts active at neutral pH.So it is a further challenge to develop HER catalysts working efficiently in all pH.Transition metal phosphide was formed by phosphorus atoms into the crystal lattice transition metal compounds,has alloy's characteristic,good electrical conductivity.In this paper,we successfully synthesized cobalt phosphate with different morphorology and explorated the performance of Hydrogen evolution reaction?HER?.The main work is as follows:1.Based on carbon cloth substrate,firstly using hydrothermal method grew CoF₂·4H₂O NS array on carbon cloth,and then adopting the method of low temperature phosphating prepare CoP NS array on carbon cloth?CoP NS/CC?.We found that CoP NS array has highly active catalytic performance,good stability and100%of Faraday efficiency.In acidic,neutral and basic media,Overpotentials of 92?160 and 90 mV are required for CoP NS/CC to approach current density of-10mA/cm²,respectively.2.Based on carbon cloth substrate,firstly using hydrothermal method grew Co?OH?F NW precursor on carbon cloth,then the method of low temperature phosphating prepared CoP NW,next Co?OH?F NS was electrodeposited on CoP NW,later Co?OH?F NS was transformed into CoP NS via the method of low temperature phosphating.The CoP NS/CoP NW/CC,as a 3D hydrogen-evolving catalyst,shows excellent catalytic performance and good stability and 100%of Faraday efficiency.Overpotentials of 90?174 and 84 mV are required for CoP NS/CoP NW/CC to approach current density of-10 mA/cm²,respectively.3.Based on carbon cloth substrate,Firstly,carbon cloth was grown cube–shaped Co?CO₃?_0.5?OH?/CC through the hydrothermal method.Then flower-like CoP NS/CC was synthesized with the low temperature phosphating mothed.It showed the high electrochemical performance to apply in acidic,neutral and alkaline medium to produce hydrogen for hydrogen evolution.Overpotentials of 87,110 and 55 mV are required for CoP NS/CC to approach current density of 10 mA/cm²,respectively.