Zinc-based Semiconductor Morphology, Surface Properties Regulation And Application

The fast development of industry brings the serious problem about the energy and water pollution.The photocatalysis based on the utilization of light energy and the adsorption technique based on porous materials have shown the promising application in the filed.It is important to design the high-efficient and low-cost catalysts and adsorbing materials.The Zn can combine with different anions(organic ligands),thus giving the nano-materials with versatile structure.In this thesis,we have constructed the different Zn-based materials with good catalytic activity and adsorbing performance based on tuning the kinds of the anions(ligand).The content as follows:I.The commercial zinc oxides(C-ZnO)have low cost,and can be easily obtained with the large quantity,which is favorable for the practical application of ZnO-based mateirals.By selecting C-ZnO with different micro-structure(size and crystallinity),we have demonstrated the high activity of C-ZnO for the degradation of the dyes.The C-ZnO gives about 3.8,7.4 and 5.2 time higher activity than P25 Ti02 for the degradation of the rhodamine B(RhB),methyl orange(MO)and methyl blue(MB),better than the ZnO reported in previous works.XPS,Raman and Photoluminescence tests indicated that the surface defect(surface hydroxyl oxygen)and crystalline degree have important effect on the photocatalytic activity.After compounding with Ag,the catalytic activity of C-ZnO can be dramatically enhanced,and Ag/C-Zn0-1 showed the record-high activity for the degradation of RhB,MO and MB(about 9.5,13 and 50 times of that for P25 Ti02).The work would be important for promoting the practical application of ZnO-based materials.2.Based on the liquid-solid reaction,the one-dimensional hierarchical 2Zn3(P04)2 was prepared by using zinc stearate as Zn source.The Zn3(P04)2 showed good performance for the photocatalytic hydrogen evolution(PHE)with no need of Pt co-catalyst in Na2S+Na2S03 aqueous solution.The analyses indicated that the Zn3(P04)2 was transformed into ZnS in the reaction,and the activity for PHE was originated from the ZnS.The work not only provided the route toward the one-dimensional hierarchical Zn3(P04)2,but also useful way for the construction of ZnS-based catalyst for PHE by using Zn3(P04)2 as template.3.ZIF-8(the complex of 2-methyl imidazole and Zn),having plentiful pores and large surface area,are one kind of semi-conductor with good adsorption performance.We have developed the new route for the preparation of the one-dimensional ZIF-8 nanotube by using the Zn-ethylene glycol as Zn source.By changing the reaction time,the length of ZIF-8 nnaotubes can be adjusted.At the same time,a series of the experiments indicated that the ZIF-8 nanotubes have been formed by the gradual ripening of nanoplates formed at the initial step under solvothermal condition.The ZIF-8 nanotubes have showed the better performance for the dye(RhB)adsorption than the common ZIF-8 with the polyhedral structure,which should be relative with its special one-dimensional tubular structure.