Study On The Modification Of Sulfide Solid Solution And The Performance Of Photocatalytic Water Splitting For Hydrogen Production

The energy and environmental problems that caused by the use and exploitation of fossil fuels are becoming more and more serious.Hydrogen as a kind of clean and non-pollution energy is considered to be the best alternative to fossil fuels.The photocatalytic water splitting to produce hydrogen by using semiconductor is an important measure to solve the energy crisis and environmental pollution.Sulfide solid solution is widely studied due to its strong absorptive capacity to visible light and good photocatalytic activity for hydrogen production.In this paper,the modification of sulfide solid solution and the performance of photocatalytic hydrogen production are mostly studied.It includes two aspects:1.Using non-toxic red phosphorus as phosphorus source and ethanolamine as solvent,Ni2P was prepared and Highly dispersedly in situ loaded on surface of Cd0.5Zn0.5S photocatalyst by low temperature solvothermal method.The loading mass of Ni2P impact on the morphology,structure,optical properties and photocatalytic activity of photocatalysts were studied.The result indicates that absorption of catalysts visible light is enhanced and activity of hydrogen evolution increased significantly after loading Ni2P.The hydrogen evolution rate reaches the maximum with the loading mass of Ni2P reaches 4wt%,which is about 5 times that of hydrogen evolution rate of pure Cd0.5Zn0.5S.The highest H2 evolution rate achieves 65.6 μmol/h and quantum efficiency of monochromatic light(420nm)reaches 29%under the optimized conditions,and show excellent stability during 20 h reaction.The formation of Ni2PCd0.5Zn0.5S intimate interface contact,leading to charge migrate effectively from Cd0.5Zn0.5S to Ni2P is considered to be an important reason for the improvement of photocatalytic hydrogen evolution activity.2.ZnIn2S4 photocatalyst was modified during hydrothermal preparation process using polyethylene glycol(PEG-4000)as metal ion complexing agent and template.The additive amount of PEG impacts on the structure,optical properties and photocatalytic performance of catalyst was studied.The study show that lattice spacing of the catalyst(006)face is increasing and position of the diffraction peak successively shift to a small angle with the raise of PEG by degrees.In addition,the UV-vis absorption edge will also have blue shift,resulting in the increase of the energy band;the grain size will increase;the adsorption of triethanolamine gradually increased and Photocatalytic activity of hydrogen production first increased and then decreased.In the system of triethanolamine as electron donor,the hydrogen production rate reaches the maximum at 0.07g PEG.Non-noble metal NiS can further improve the photocatalytic activity as cocatalyst and shows good stability.