| As one kind of green,inexhaustible energy,solar energy have been attracting attention by scientists for a long time.The use of sunlight to break down water to produce hydrogen has long been known as the"holy grail of chemistry".To date,photocatalytic hydrogen production is still far away from industrialization,mainly due to the low hydrogen production efficiency and the stability of photocatalysts.Based on the principle of photocatalytic hydrogen production,this paper takes into account several major problems existing in photocatalysts at present（1）narrow range of light absorption;（2）easy recombination of electron-hole pairs;（3）poor stability;（4）Surface reaction speed is slow,and so on.The local isocalliative effect of noble metal nanoparticles（LSPR）is ocalliative element noble metal-semiconductor composite photocatalyst is constructed to alleviate the above problems.The main results of this thesis are as follows:1.Combined with galvanic replacement and co-reduction methods,a novel strategy was investigated to rapidly synthesize uniform Au-Ag HNPs with good control over the hollow interior diameter and shell thickness to easily obtain tunable optical properties.Compared to solid nanoparticle,Au-Ag HNPs has unique advantages.The position of LSPR peak could be effectively adjusted between 490 nm and 713 nm by decreasing the cavity size of the Au-Ag hollow nanoparticles from 35 nm to 20 nm.we found that Au-Ag HNPs with a complete shell and a thickness of 5 nm have stronger LSPR effect,which can effectively promote the improvement of P25 photocatalytic performance.The plasmon-enhanced photocatalytic H2evolution of alloy nanoparticles with different cavity sizes was investigated.Compared with pure P25（TiO2）,intact and thin-shelled Au-Ag HNPs-supported photocatalyst exhibited an increase in the photocatalytic H2 evolution rate from 0.48μmol h-1 to 4μmol h-1 under full-spectrum irradiation.This improved photocatalytic performance was likely due to the plasmon-induced electromagnetic field effect,which caused strong photogenerated charge separation,rather than the generation of hot electrons.2.Au-Agx HNPs with tunable LSPR peak achieve different degrees of overlap with CdS absorption spectra,and different degrees of PRET mechanisms are achieved.We investigated the photocatalytic performance of Au-Agx@CdSy with different CdS coating thicknesses.More importantly,the photocatalytic performance of Au-Agx@CdS90 with different degrees of energy transfer caused by different degrees of spectral overlap was explored.The results demonstrate the degree of overlap between noble metal and semiconductors affects PRET to further enhance photocatalytic H2 evolution,which was beneficial to the design of new plasmon photocatalysts.3.The plasma coupling generated by the interaction between metal nanoparticles can further amplify the electromagnetic field energy centered on the nanostructures in the near field.Au-Ag HNPs are hybridized into one-dimensional nano-chains（NCs）,and the CdS is coated to form an Au-Ag@CdS composite photocatalyst.Under visible light irradiation（λ>420 nm）,Au-Ag@CdS light The H2 released by the catalyst can reach 8.12 mmol h-1 g-1.The coupling effect of this alloy nanochain structure can produce a stronger LSPR effect,effectively promote the separation of electron and hole pairs of CdS,and thus improve the photocatalytic performance. |
