Optimized Charge-carrier Process In BiOCl Nano-materials For Boosting Photocatalytic Performance

Our current energy infrastructure relies heavily on fossil fuels,yet the associated environmental pollution,energy crisis,and climate policy may be gradually changing it and driving the global demand for environmentally friendly and sustainable energy production.The development of efficient semiconducting catalysts mimicking the catalytic function of natural photosynthesis to generate chemical fuels from water and sunlight,presents a promising green production mode from renewable sources.However,this topic has not been fully explored for the highly efficient photocatalytic system.In view of this,we systematically study the effects of material surficial engineering on photocatalytic systems and hope to promote the development of rational design of efficient photocatalysts.The work of this paper will be carried out from the following two directions:1)By practicing the surface-selective assembling procedure of Pd nanoparticles on BiOCl nanosheets,we have achieved the cooperative utilization of the functional hole-flow interfaces and maximize their transferring for the fully regulation of charge carrier,which is further integrated with the intrinsic charge distribution in anisotropic semiconductor.2)In the secod part,we have investigated the influence of oxygen vacancy on the heterostructure fabrication and photo-induced charge-carrier processes between the prototypical models of MoS₂,and BiOCl,where the relevant surface-defect-engineering in multilateral heterostructure photocatalyst had seldom been reported.This paper is divided into the following four parts:The development of photocatalysis is firstly introduced in this manuscript.And the relevant mechanism of semiconductor materials,which applied in photocatalysis,was also illustrates.Besides,the recent investigations on photocatalysis are summarized.Here,some widely accepted methods for constructing high efficiency photocatalysts were summarized,whose reasonability and application mechanisms of these methods were theoretically and practically discussed.Combined with the latest reported research,we thus provide a feasible strategy for the fabrication of high efficiency photocatalyst.In this work,the anisotropic bismuth oxyhalides nanomaterials were used as models.Through theoretical calculation and selective photo-deposition experiments,we determined the enriching of electrons and holes in different crystal facets.By practicing the facet-select assembling procedure of co-catalyst,we achieved the spatially separated reaction sites,single-function electron/hole-flow interfaces and maximize their transferring,which is closely intertwined with the anisotropic charge-distribution of nanosheet morphology.As a result,our established system achieved an enhanced performance in photocatalysis.In the second part,starting from the defect engineering of materials,we synthesized the O-deficient BiOCl nanosheets by hydrothermal method.Then,by utilizing the oxygen vacancy on the surface of BiOCl,molybdenum sulfide was loaded through thermal backflow,whose established structure was different from van der Waals heterostructure.Meanwhile,various BiOCl/MoS₂ composites with distinct properties were obtained by calcining-mediated controlling on the concentration of vacancy.Through a series of characterization and experiments,we proved that the surface vacancy not only played an important role in the fabrication of MoS₂-BiOCl,which made the structure obviously differ from van der Waals heterostructure,but also made a major contribution to the enhancement of charge-carrier-involved processes.In the final chapter,we summarized the conclusions obtained from the above-mentioned work.Further combined with the recent progress on nanomaterials in the field of semiconducting photocatalysis,we proposed some new ideas for the fabrication of high performance photocatalysts.