Preparation Of Biomass Graphene And Its Application With Cu NPs In Photocatalytic Hydrogen Production

Graphene?G?has been widely researched and applied because of its huge theoretical specific surface area and excellent photoelectric performance.The application of graphene to environmental governance and energy storage and conversion is a current research hotspot.Eucalyptus robusta Smith,as a fast-growing and abundant tree species,has good economic value,but there is a small amount of waste in industrial applications.Considering the high cost and non-scalability of many graphene preparation processes,we use abandoned eucalyptus tissue as material to prepare biomass graphene which can be produced massively.And we apply the biomass graphene to the research of photocatalytic hydrogen production,which has the potential to solve the energy crisis,by combining it with the research of metal plasmon resonance enhanced photocatalysis,to provide new ideas of development of stable and efficient photocatalyst.The research content and results are as follows:?1?Biomass graphene was prepared by carbonization at low temperature and activation at high temperature by using waste eucalyptus tissue as carbon precursor.The effect of different amounts of K₂CO₃ as the activator on the graphitization of teucalyptus carbonization product was discussed.And the optimal mass ratio of K₂CO₃ to the carbonization product was 3:1.And at that mass ratio,KHCO3 and CH3COOK were added as activators for activation to compare the effects of different activators on the activation process.It was found that 3D network graphene was prepared when KHCO₃ and K₂CO₃were used as activator while large-diameter layered graphene was prepared when CH₃COOK was used.?2?Based on the graphitization degree and pore structure of the prepared sample,G-K2CO3-3 was selected as the raw material for subsequent experiments.Biomass graphene-modified CdS binary photocatalyst?CdS/G?was obtained by hydrothermal method.The effect of different graphene content on CdS/G photocatalytic hydrogen production performance was discussed,and the optimal graphene content was optimized to be 3.66%.Combining the characterization results of the sample's micro-morphology and photoelectric performance,the role of graphene in the binary catalyst was analyzed.?3?Cu nanoparticles?Cu NPs?were further deposited on the CdS/G binary photocatalyst by in-situ photoreduction to obtain the ternary composite photocatalyst,which is Cu/CdS/G.The successful loading of Cu NPs was verified by XRD,XPS and other characterization methods,and it was found that the contact between Cu NPs and CdS will form a Schottky barrier,which is helpful for the transmission of photogenerated electrons.The morphology and light absorption characteristics of Cu/CdS/G were observed.Combined with the result of photocatalytic hydrogen production,it was found that the plasma resonance of Cu NPs greatly improved the hydrogen production capacity of Cu/CdS/G.A cycle stability test was conducted on 6.0wt%Cu/CdS/G-3,and it was found that the addition of biomass graphene and copper helps to improve the stability of the photocatalyst.Combining the test results of fluorescence,photocurrent,Mott Schottky and mentioned previously,the mechanism of Cu/CdS/G photocatalytic hydrogen production was speculated.