摘要：Energy crisis and environmental problems urgently drive the proposal of new strategies to improve human wellbeing and assist sustainable *** this end,scientists have explored many metal oxides-based photocatalysts with high stability,low cost,earth abundance,and potentially high catalytic activity relevant for key applications such as H2O splitting,CO2 reduction,N2 fixation,and advanced oxidation of *** these metal oxides,oxygen vacancies(OVs)are ubiquitous and intrinsic defects with pronounced impacts on the physicochemical properties of the catalysts,which may open new opportunities for obtaining efficient metal *** thorough understanding of the structural and electronic nature of OVs is necessary to determine how they serve as catalytically active *** this review,we summarize the origin of OVs,the strategies to introduce OVs,as well as the fundamental structure-activity relationships to relate these crystal defects to catalyst properties including light absorption,charge separation,*** emphasize the mechanism of OVs formation and their effects on the intrinsic catalytic characteristics of the metal *** also present some multicomponent catalytic platforms where OVs contribute to catalysis via ***,opportunities and challenges on engineering defects in photocatalysts are summarized to highlight the future directions of this research field.

摘要：Unveiling the pore-size performance of metal organic frameworks(MOFs)is imperative for controllable design of sophisticated ***,UiO-66 with distinct macropores and mesopores were intentionally created and served as substrates to create advanced CdS/UiO-66 *** pore size impacted the spatial distribution of CdS nanoparticles(NPs):CdS tended to deposit on the external surface of mesoporous UiO-66,but spontaneously penetrated into the large cavity of macroporous UiO-66 *** to unit amount of CdS,the photocatalytic reaction constant of macroporous CdS/UiO-66 over 4-nitroaniline reduction was~3 folds of that of mesoporous counterpart,and outperformed many other reported state-of-art CdS-based catalysts.A confinement effect of CdS NPs within UiO-66 cage could respond for its high activity,which could shorten the electron-transport distance of NPs-MOFs-reactant,and protect the active CdS NPs from *** finding here provides a straightforward paradigm and mechanism to rationally fabricate advance NPs/MOFs for diverse applications.

摘要：晶格氧介导的氧化还原反应可以将有机物选择性氧化为高附加值产物,是实现生物质资源高值化利用的重要途径.其关键科学难题在于:如何使催化材料同时具有较低的晶格氧(O_(L))结合能以产生活性O_(L),以及较高的O_(L)结合能以保持其在催化过程中的结构稳定性.在本工作中,我们制备了无定形锆掺杂的锰氧化物(amor-Zr:MnO_(x))催化材料,并证实其同时具有高活性的O_(L)以及高稳定性的O_(L).以5-羟甲基糠醛(HMF)的选择性氧化为反应模型,amor-Zr_(0.2)MnO_(x)催化剂实现了HMF的高效选择性氧化,产物中2,5-呋喃二甲酸(FDCA)的选择性高达99%,1小时内FDCA产率高达3600μmol_(FDCA)g_(cat)^(-1)h^(-1),在类似反应条件下其性能优于大多数Mn基和相关过渡金属氧化物基催化材料.实验和理论研究表明,amor-Zr:MnO_(x)的优异性能源于其同时含有两种O_(L).首先,锆提高了锰相邻的O_(L)的氧化活性,并促进了反应后氧空位对O_(2)的吸附/活化,获得活性O_(L)且同步促进催化反应中O_(L)的再生;锆相邻的O_(L)具有较低的反应活性,有利于催化材料保持结构稳定性.本工作有望为理解晶格氧的氧化机制以及高活性催化材料的设计提供思路.

摘要：构建高度定向、有序的一维/二维异质结催化材料是解决能源和环境危机的重要途径.本工作报道了在不添加表面活性剂条件下,纳米层状双金属氢氧化物(NiZn-LDHs)可以在生长过程中自发调控其生长晶面,并通过一种非经典取向结合生长机制,形成高度定向、有序的一维/二维异质结构.定向、有序异质结结构的形成源于一维NiZn-LDH纳米针的(101)面和二维NiZn-LDH纳米片的(100)面之间的晶格匹配.定向、有序异质结结构促使一维基元在二维基元上高度分散,而高度分散的一维NiZn-LDH富含缺陷,具有较强的CO_(2)吸附和活化能力.定向一维/二维异质结强化了一维和二维基元之间的相互作用,可加速光生电子从二维基元向含活性位点一维基元的定向传输,赋予催化材料优异的可见光光催化还原CO_(2)性能(C O的产出速率达16,950μmol g^(-1)h^(-1);CO选择性高达100%).本工作展示了各向异性纳米结构材料可以自发调控其生长行为,为高效、定向、有序的异质结催化材料的设计提供了新的思路.

摘要：将福建大田地区的铅锌尾矿用于研制铅锌尾矿水泥混合材,再用该水泥混合材与重晶石等原料制备铅锌尾矿防辐射混凝土。主要探讨了铅锌尾矿添加量对水泥混合材的强度影响,并研究了铅锌尾矿防辐射混凝土的坍落度、抗折强度和热稳定性等主要物理化学性能和防辐射性能。实验结果表明,铅锌尾矿的掺量在20wt.%(质量分数,下同)以下时,所制得铅锌尾矿水泥混合材的水泥强度等级均可达到42.5级通用硅酸盐水泥等级,且利用其制备出的铅锌尾矿防辐射混凝土防辐射性能良好。当用水量为190 kg/m^3、水泥用量为365 kg/m^3、细骨料用量为1130 kg/m^3、粗骨料用量为1844 kg/m^3时,所制得的防辐射混凝土粘聚性和保水性较好,坍落度为52 mm,表观密度为3510 kg/m^3,满足设计要求。