Surface plasmon resonance effect of Ag nanoparticles for improving the photocatalytic performance of biochar quantum-dot/Bi_4Ti_3O_(12) nanosheets

Herein,we report a novel ternary material comprised of Ag nanoparticles and carbon quantum dots(CDs),which are co-loaded using 2D Bi4Ti3O12(BIT)sheets.In this system,Ag can be applied as excited electron-hole pairs in the Bi4Ti3O12 by transferring the plasmonic energy from the metal to the semiconductor.The surface plasmon resonance of Ag can promote the electron transfer properties of the CDs,thereby improving the separation efficiency of the electron-hole pairs.Meanwhile,the CDs can act as an electron buffer to decrease the recombination rate of the electron hole.Moreover,CDs are prepared using a biomaterial,which can provide a chemical group to enhance the electron transfer and connection.The synergistic effects of CDs,Ag,and BIT enable the design of a photocatalytic application with a remarkably improved efficiency and operational stability.

Fast electron transfer and enhanced visible light photocatalytic activity by using poly-o-phenylenediamine modified AgCl/g-C_3N_4 nanosheets

Exfoliation of bulk graphitic carbon nitride(g‐C3N4)into two‐dimensional(2D)nanosheets is one of the effective strategies to improve its photocatalytic properties so that the 2D g‐C3N4 nanosheets(CN)have larger specific surface areas and more reaction sites.In addition,poly‐o‐phenylenediamine(PoPD)can improve the electrical conductivity and photocatalytic activity of semiconductor materials.Here,the novel efficient composite PoPD/AgCl/g‐C3N4 nanosheets was first synthesized by a precipitation reaction and the photoinitiated polymerization approach.The obtained photocatalysts have larger specific surface areas and could achieve better visible‐light response.However,silver chloride(AgCl)is susceptible to agglomeration and photocorrosion.The PoPD/AgCl/CN composite exhibits an extremely high photocurrent density,which is three times that of CN.Obviously enhanced photocatalytic activities of PoPD/AgCl/g‐C3N4 are revealed through the photodegradation of tetracycline.The stability of PoPD/AgCl/CN is demonstrated based on four cycles of experiments that reveal that the degradation rate only decreases slightly.Furthermore,.O2^-and h+are the main active species,which are confirmed through a trapping experiment and ESR spin‐trap technique.Therefore,the prepared PoPD/AgCl/CN can be considered as a stable photocatalyst,in which PoPD is added as a charge carrier and acts a photosensitive protective layer on the surface of the AgCl particles.This provides a new technology for preparing highly stable composite photocatalysts that can effectively deal with environmental issues.

Hydrochloric acid‐mediated synthesis of ZnFe_(2)O_(4) small particle decorated one‐dimensional Perylene Diimide S‐scheme heterojunction with excellent photocatalytic ability

The recyclable and stable ZnFe_(2)O_(4) small particle decorated one‐dimensional perylene diimide(PDI)S‐scheme heterojunction(1D PDI/ZnFe_(2)O_(4))is prepared by the hydrochloric acid‐mediated(HCl‐mediated)strategy,interestingly,the morphology of the 1D PDI/ZnFe_(2)O_(4) can also be effectively regulated by HCl‐mediated process,the existence of HCl can regulate PDI into a uniform rod structure,while the co‐existence of HCl and PDI can limit ZnFe_(2)O_(4) to become the uniform small particles.More importantly,based on the 1D rod structure of PDI and the small size effect of ZnFe_(2)O_(4),carriers can migrate to the surface more easily,which can improve the photocatalytic activity.Meanwhile,due to the appropriate energy level structure,the S‐scheme heterojunction structure is formed between PDI and ZnFe_(2)O_(4),which eliminates meaningless photo‐generated charge carriers through recombination and introduces strong redox to further enhance the photodegradation effect,thereby,1D PDI/ZnFe_(2)O_(4) exhibits excellent photocatalytic ability,under the visible light irradiation,the degradation rate of tetracycline(TC)with 1D PDI/ZnFe_(2)O_(4)(66.67%)is 9.18 times that with PDI(7.26%)and 9.73 times that with ZnFe_(2)O_(4)(6.85%).This work proposes new ideas for the assembly of magnetic organic‐inorganic S‐scheme heterojunction photocatalysts.

银基半导体光催化材料的应用研究进展

银基半导体材料具有良好的可见光响应特性和等离子体效应,因此银基材料作为可见光响应的材料广泛用于可见光光催化材料的构筑,以及应用于光分解水制氢、光降解污染物、抗菌等领域.文章从银基材料所含金属种类的不同,从一元金属到多元金属银质材料以及复合银基材料方面的研究进行了综述,并概述了其主要应用.最后,展望了银基半导体材料在光催化材料的构筑及应用方面的未来发展趋势.

全日制硕士研究生培养过程中过程控制理论及质量保障体系研究

近年来,随着我国研究生招生数量的逐年递增,现有的教育培养模式和管理方法已不能充分满足研究生的培养需求,而不断增长的研究生招生数量是国家科技进步和经济发展的必然需要,这导致了研究生培养质量上出现了参差不齐的状况,尤其是普本院校的理工科类研究生,相对来说此类学科研究生往往在本科理论基础薄弱的同时其实践技能也相对较差,因此更应该引入合适的方法对其整个研究生培养过程实现全面的监控和管理,以实现研究生培养质量上的提高。事实上质量不仅是研究生教育可持续发展的根本保障,更是研究生培养教育的灵魂,如何有效提升全日制硕士研究生的培养质量,建立更为科学、系统、规范的质量保障体系,已逐渐成为我国研究生教育界乃至全社会关注的热点问题,为避免主客观因素的影响,本文通过分析硕士研究生培养过程中的各个环节后,发现培养过程控制的单向性是当前高校研究生培养质量无法很好地满足社会需求的一个关键原因,当出现干扰作用时,未能实时有效地检测培养对象的培养质量,以及进行及时反馈,达到完善培养过程的最终目的。