Structure Controlled,Photocatalytic And Electrochemical Properties Of Hollow Nanocomposites

Today,the traditional energy can no longer meet people's growing needs and has led to a series of serious environmental problems.Photocatalytic technology and lithium-ion battery technology as new type of environmentally friendly energy has now become the focus of research.Photocatalysis transforms endless solar energy into our directly available chemical energy.Lithium-ion batteries convert energy and chemical energy into one another.Both are recyclable and eco-friendly.How to design a suitable material structure and composition will be the key to promote the progress of photocatalysis and lithium-ion technology.Hollow materials because of large specific surface area,active sites and other characteristics are widely used in catalytic reactions and lithium storage.In the catalytic reaction,the hollow structure photocatalyst material has the advantages of good surface permeability,large reaction contact area,large number of active sites and high absorption and utilization rate of visible light,which can greatly increase the efficiency of the catalytic reaction.In addition,in the lithium reaction system,hollow structure with high conductivity,surface active sites,you can embed more features such as lithium-ion,and can be very good to alleviate the cycle of charge and discharge in the material caused by the volume expansion,Thus effectively improve the electrochemical performance.The main contents of this paper are as follows:1.We precisely controlled the structure and composition of the composite photocatalyst.We synthesized nanocubes?CoS/SnS₂ NCs?uniformly assembled with CoS nanoparticles and SnS₂ nanosheets by sulfidizing CoSn?OH?6 precursors,and synthesized bis Metal sulfide cocatalyst and CdS quantum dots to form a composite photocatalyst.Here,we prepared uniform CoS/SnS₂ single-shell hollow nanocubes?SSNCs?and CdS nanoparticles as a visible light absorber.The non-noble metal CdS/CoS/SnS₂ SSNCs composite catalysts exhibited high efficiency visible light driven photocatalytic hydrogen evolution rate?1290.4 ?mol/h?,much than the hydrogen production rate of CdS/CoS/SnS₂ solid nanocubes?713.2 ?mol/h?,CdS/CoS/SnS₂ double-shell hollow nanocubes?1185.1 ?mol/h?and noble metal-based CdS/Pt?263.8?mol/h?.Due to the higher conductivity of CdS/CoS/SnS₂ SSNCs,the separation of photo-generated electron-hole pairs is improved,and the multi-reflection of visible light and the large specific surface area of the hollow structure improve the utilization of visible light so as to enhance light Catalytic hydrogen production rate.This experiment helps to design and prepare other non-noble metal photocatalyst with specific structure to achieve more effective photocatalytic application.2.We used polystyrene?PS?sphere as templates,polydopamine?PDA?as a nitrogen-containing carbon source to adsorpt metal ions,designed and synthesized a double-layer graphene coated hollow carbon sphere with metal and N-doped to form nanocomposites?G/M-N-HCS/G,M=Fe,Co?.Double-layer graphene plays an important role in improving the electron-transporting ability and the stable structure of the material.Metal and N-doping increase the number of active sites in the hollow carbon sphere and play an important role in improving the conductivity and capacity of the material.The G/Fe-N-HCS/G material with initial discharge capacity of 1636,4 mA h g^-1,charged 829.1mA h g^-1 at 1A g^-1 and a coulombic efficiency of 50%rate.