The Preparation Of Covalent Organic Polymer And Its Application In Energy Conversion

In recent years,with the aggravating of environmental pollution brought by the using of fossil energy and the exhaustion of fossil energy,how to develop clean and renewable energy has drew the attention of worldwide.As a kind of renewable energy with high energy density and no pollution,hydrogen energy is considered as a kind of clean energy that can be an alternative to fossil energy.Meanwhile,hydrogen oxygen fuel cell is regarded as an ideal power supply device due to its high energy conversion efficiency and pollution-free production.One of the ideal energy conversion systems in the future is that collecting solar energy by photocatalytic water splitting,and using hydrogen oxygen fuel cells convert hydrogen energy into electrical energy which can be directly used by mechanical equipment.However,at present,the energy conversion process of photocatalytic water splitting to hydrogen and hydrogen oxygen fuel cell is less efficient,so the using of energy conversion catalyst is inevitable in the process of hydrogen generation and hydrogen energy using.Here,we developed a new 2D N-rich covalent organic polymer(termed as COPHM)through polymerization of hexaketocyclohexane and melamine and further study the catalysis of COPHM derivatives in the energy conversion process.Firstly,titanium dioxide was modified by in-situ growth of COPHM.By changing the ratio of reactants of COPHM,different covalent organic polymer-modified titanium dioxide materials(TiO2@COPHM-0.1?TiO2?COPHM-1?TiO2@COPHM-10)were prepared,and the hydrogen generation experiment Was carried out.Compared with raw TiO2(3.13 eV),TIO2?COPHM-1 has a narrower band gap(2.53 eV)and better visible light absorption capacity,which means that COPHM modified TiO2 has higher energy utilization efficiency.In the hydrogen production experiment,TiO2@COPHM-1 showed excellent hydrogen generation performance.The hydrogen generation rate of TiO2?COPHM-1 was as high as 162.7 ?mol h-1 under simulated sunlight,while the raw TiO2 only 51.3 ?mol h-1.In addition,COPHM derived materials also shown excellent performance in electrocatalytic oxygen reduction.COPHM derivative catalyst Fe@COPHM-F127 was prepared with the aid of anionic surfactant F127.Fe@COPHM-F127 had an onset potential of 1 V which equal to Pt/C,a half-wave potential of 0.87 V which 40 mV higher than Pt/C.Meanwhile,Fe@COPHM-F127 exhibited excellent stability and methanol tolerance in the catalytic process.