| Hydrogen peroxide is a basic chemical that plays an important role in various industrial fields.However,the Anthraquinone method preparing hydrogen peroxide in industry faced with serious problems such as high energy consumption,high pollution and potential safety hazards.Therefore,it is of great social and economic significance to build decentralized,green and safe synthetic method for hydrogen peroxide production.The synthesis of hydrogen peroxide by two electron oxygen reduction or two electron water oxidation have been widely concerned in recent years.However,unlike the traditional four electron oxygen reduction or water oxidation process,the generation of hydrogen peroxide is thermodynamically unfavorable.Therefore,the researchers developed the high-performance catalysts through the rational design of the active sites as well as the surface engineering modification of the catalysts.However,accurate construction of ideal coordination structures and fabrication of the overall efficient electrode materials are still the priorities.On the other hand,the developed hydrogen peroxide synthesis system cannot be directly utilized due to the existence of electrolyte ions,which hinders its further development towards industrialization.Therefore,it is urgent to fully utilize the important industrial value of hydrogen peroxide on the basis of ensuring efficient and green production of hydrogen peroxide.Based on the above considerations,the research contents of this dissertation mainly include the following three aspects1.A variety of single atom catalysts coordinated by oxygen functional groups used for efficient cathodic oxygen reduction towards hydrogen peroxide production.Although single metal sites modified by oxygen containing functional groups have been proved to be effectively enhance the activity and selectivity of hydrogen peroxide production via dioxygen reduction.However,the existing"coordination-pyrolysis-rinsing"synthesis method cannot achieve accurate control of the micro coordination structure of the catalysts,which is hard to establish a unified structure model to fully understand the structure-activity relationship.Therefore,a one-step solvothermal method was proposed in this study.Polar aprotic dimethyl sulfoxide（DMSO）was used to provide a constant coordination environment,a series of single atom catalysts（SACs）with active structures of-CO3M,-CO2M and-COOM（M:Mo,W,Nb）were constructed on lightly reduced graphene oxide（mrG）.All three catalysts with different metal species prepared have good performance in hydrogen peroxide production,while Mo SACs/mrG obtained the best selectivity and reactivity under neutral conditions(η～94.5%,Vonset=0.65 V vs.RHE,Tafel slope=53 m V/dec).Theoretical research indicates that,all M-Ox-C moieties have an overwhelming preference for forming H2O2 as a result of the downhill reaction2.Heterostructure photoanode used for the efficient hydrogen peroxide production via water oxidation.On the basis of the surface engineered photoanode towards efficient water oxidation hydrogen peroxide production raised by previous research,this chapter enhanced the light absorption and carrier separation efficiency of the photoanode by constructing and optimizing the multilayer heterostructure.First,BiVO4/WO3 heterostructure was carefully prepared with high carrier separation efficiency（92.1%）and transfer efficiency（75.4%）（at 1.23 V vs.RHE potential）,which was improved by the in situ W ion doping in the BiVO4/WO3.At the same time,through texture optimization,the transparency of the photoanode is also improved without sacrificing the carrier utilization efficiency.Finally,SnO2-x/BiVO4/WO3 photoanode with high transparency,high hydrogen peroxide production selectivity and high current density was obtained by depositing SnO2-x passivation layer,yielding 1.13μ·mol/（min×cm2）H2O2 production rate（at 1.23 V vs.RHE potential）,providing a good foundation for the future high-performance PV/PEC driven hydrogen peroxide production device.3.Self-cycled photo-Fenton-like system based on an artificial leaf with a solar-to-H2O2 conversion efficiency of 1.46%.Considering that the existing hydrogen peroxide production system cannot used directly,this study provides a new route for above problem by designing the in-situ hydrogen peroxide production/consumption system.In this chapter,through coupling the photoanode and cathode designed in the previous two chapters,with optimized dynamics,the artificial leaves with high conversion efficiency were carefully designed and successfully applied to the self-cycled photo-Fenton system,realizing the construction of a sustainable reaction system for wastewater treatment.The artificial leaf is supported by SnO2-x/BiVO4/WO3photoelectrode and PTFE modified Mo single atom catalysts/mrG（PTFE@Mo-SACs/mrG-GDE）,which achieved 0.77μmol/（min·cm2）H2O2 production rate under AM 1.5illumination without external bias voltage,which is equivalent to 1.46%unbiased solar hydrogen peroxide conversion efficiency（SHy E）.Secondly,through the catalysis of Mn（Ⅱ）species in bicarbonate electrolyte,H2O2 generated by artificial leaves can be immediately activated into main ROSs such as·OH,·O2-and 1O2,while Mn（Ⅳ）species obtained by oxidation can be reduced on the photo driven cathode,realizing the recycling of Mn（Ⅱ）/Mn（Ⅳ）species.Finally,large-scaled artificial leaves（70 cm2）have shown good performance in removing organic pollutants for more than a month under the supply of only water,oxygen and sunlight. |
