Study On Synthesis And Electrochemical Hydrogen Evolution Reaction Performance Of Transition Metal(Mo,Re)Phosphides

With the rapid development of modern technology,the demand for energy in the entire society is gradually increasing.The reserves of traditional fossil fuels are insufficient,and the problems of environmental pollution caused by their combustion are also serious.Therefore,suitable clean and renewable energy sources are urgently needed in the sustainable development of society.As a clean energy with zero carbon emissions,hydrogen is an ideal substitute for traditional fossil energy sources.The electrochemical catalytic hydrogen evolution reaction(HER)is a green hydrogen production method,but the efficient electrochemical method for produc:ing hydrogen depends on excellent performance HER catalyst.Therefore,the preparation of high-efficiency,cheap,and stable electrocatalysts is currently a problem to be solved.Transition metal phosphides(TMPs)have been widely reported because of their excellent HER electrochemical catalytic activity.In-depth study of the application of such nanomaterials in this field is not only an important part of basic scientific research,but also has important display significance.Based on the above research background,this paper mainly explores the synthesis of transition metal(Mo,Re)phosphides and their electrochemical catalytic HER performance.We used adenine and molybdenum trioxide as precursors to synthesize one-dimensional nitrogen-doped molybdenum phosphide(N-MoP)nanorod catalysts through phosphating,and systematically studied the electrochemical catalysis of molybdenum phosphide nanocatalysts for HER Activity and mechanism.In order to further reveal the effect of phosphating on the electrochemical catalytic performance of transition metals,we synthesized rhenium phosphide(Re2P,Re3P4)nanocatalysts with different degrees of phosphating,and explored their electrochemical catalytic HER performance.The specific research content of this paper is as follows:(1)We demonstrated an in situ thermal phosphorization strategy based on MoO3-adenine(MoAD)hybrids for the construction of crystallographically interconnected nitrogen-doped molybdenum phosphide(N-MoP-T,T is the temperature of synthesis)nanocrystals consisting of abundant grain boundaries for high-efficient hydrogen evolution reaction(HER).The as-synthesized tandem N-MoP-800(which obatained at 800?)nanocrystals exhibited remarkable HER activity,with overpotentials of 125 and 175 mV at a cathodic current density of 10 mA cm-2 and corresponding Tafel slopes of 69 mV dec-1 in alkaline and acidic conditions.In addition,N-MoP exhibited long-term durability of 12 hours over a wide pH range.To investigate the performance characteristics of MoP,nitrogen-doped molybdenum disulfide(N-MoS2)and molybdenum dioxide(N-MoO2)nanorods were synthesized from the same precursor(MoAD),respectively.The work presented here will not only unravel the potential of adenine in nanocatalysts development but also reinforce the exploitation of the sustainable raw materials for disparate nanocatalysts.(2)Using ammonium perrhenate(NH4ReO4)as raw materials and sodium dihydrogen hypophosphite(NaH2PO2)as P source,rhenium phosphide(Re2P and Re3P4)with different degrees of phosphating were prepared based on the in situ phosphating method.The synthesized Re2P and Re3P4 exhibited very good electrocatalytic activity under both acidic and alkaline conditions.The overpotentials of Re2P at a cathode current density of 10 mA cm-2 were 140 and 90 mV,respectively,and the corresponding Tafel slopes were 62 and 74 mV dec-1.Furthermore,Re2P also showed a long-term durability of 12 hours in a wide pH range.