硫鸟嘌呤修饰的Mn:ZnS QDs磷光探针检测铂(Ⅲ)

通过水相合成法制备了硫鸟嘌呤(TG)修饰的锰掺杂硫化锌量子点(TG-Mn:ZnS QDs)。加入Pt⁴⁺后,Pt⁴⁺会与硫鸟嘌呤上的氮原子结合形成N-Pt⁴⁺配位结构附着在TG-Mn:ZnS QDs的表面,随着Pt⁴⁺浓度的增加,TG-Mn:ZnS QDs-Pt⁴⁺体系发生电子转移而导致磷光逐渐被猝灭,基于此构建了检测Pt⁴⁺的磷光探针。实验中考察了p H、时间对Pt⁴⁺猝灭TG-Mn:ZnS QDs磷光强度的影响。在最佳实验条件下,Pt⁴⁺浓度在0.06~2.4μg/mL范围内与TG-Mn:ZnS QDs的磷光强度呈良好的线性关系y=0.0884x+0.2319,R²=0.991,方法检出限(3σ/n)为1.3μg/mL。该磷光探针适用于实际样品中Pt⁴⁺含量的测定。     

高分散还原态Pt基催化剂的制备及其NO氧化的催化性能

Pt⁰被认为是NO氧化的活性物种,而催化剂的制备方法对活性物种的含量起着决定性作用。本文采用非惰性气氛保护的改性醇还原-浸渍法(MARI)合成了高分散高Pt⁰含量的1% (w, 质量分数) Pt/SiO₂-Al₂O₃催化剂(MA-Pt/SA)。X射线粉末衍射(XRD)、CO-漫反射傅里叶变换红外吸收光谱(CO-DRIFTS)和透射电镜(TEM)表征证实在550 ℃焙烧3 h后催化剂的Pt颗粒仅有3.8 nm。同时,X射线光电子能谱(XPS)和H₂-程序升温还原(H₂-TPR)结果表明催化剂具有高Pt⁰含量(60.3%)。模拟柴油车尾气气氛进行活性测试,并与传统浸渍法制备的1% (w) Pt/SiO₂-Al₂O₃催化剂(C-Pt/SA)对比,结果显示MA-Pt/SA具有优异的催化氧化性能,其NO最大转化率高达74%,比C-Pt/SA的NO转化率高了23%。经670 ℃高温老化15 h后,老化的MA-Pt/SA的NO转化率仍然高达69%。此外NO + O₂共吸附原位漫反射傅里叶变换红外吸收光谱(in situ DRIFTS of NO + O₂ co-adsorption)表明高的Pt分散度和高Pt⁰含量能够促进中间物种桥式硝酸盐的生成及分解,进而导致了优异的NO氧化活性。最后,利用同样方法将Pt的负载量降低至0.5% (w)制备催化剂,NO转化率仍达64%。这种制备方法能够获得低贵金属高性能的Pt基催化剂。     

光催化乙醇水溶液脱氢的EPR研究

本文报道,在含有Pt/CdS的乙醇水溶液中分别加入不同俘获剂: POBN (α-(4-pyridyl N-oxide)-N-tert-butyl nitrone), MV²⁺(methylviologen), NB(nitrosobenzene)或 TCNQ(7,7,8,8-tetracyano-p-quinodimethane),在可见光(λ≥450nm)照射下,光催化产氢及其光催化脱氢机理的EPR(电子顺磁共振)研究。结果表明,在Pt/CdS-CH₃CH₂OH/H₂O体系中进行可见光反应3小时,其产氢量相当高(0.0136 mmol);在加入POBN的体系中,由于其俘获了CH₃HOH自由基而使产氢量降低了三分之二,这说明由CH₃HOH经H⁺产氢比水分解经H⁺产氢更容易。在加入TCNQ或NB的体系中,由于其俘获了电子(e^-)或自由基,因而都未检测到氢气;这说明在可见光照射下,Pt/CdS催化乙醇水溶液脱氢的机理是经由: H⁺+e^-→Ñ→1/2H₂.     

La掺杂钛酸钙光催化剂在可见光下分解水制氢的影响因素

以柠檬酸为络合剂, 采用溶胶-凝胶法制备了钙钛矿型光催化剂Ca_0.99La_0.01TiO₃, 利用X射线衍射仪(XRD)、 扫描电子显微镜(SEM)、 紫外-可见漫反射光谱仪(UV-Vis DRS)等对光催化剂材料进行了表征, 并考察了N掺杂对光催化剂催化效果的影响, 探究了可见光条件下, Ca_0.99La_0.01TiO_3-xN_x在不同Pt负载量及不同种类牺牲剂中光催化分解水的产氢量, 并进行相关荧光猝灭分析. 结果表明, 在可见光条件下, Pt负载量为1%且掺杂N的钙钛矿光催化剂在Na₂SO₃/Na₂S作为牺牲剂时, 光催化分解水的产氢量最高.     

以无机亚磷酸为牺牲剂光化学法制备无定形Ni(OH)2助催化剂用于光催化产氢

随着环境污染和能源危机的加剧,发展可持续能源迫在眉睫.氢气被认为是可以替代化石能源的最有前途的能源之一,且光催化分解水产氢是一种可以将太阳能转化为氢能的环境友好的方法.n型半导体材料石墨C3N4 (g-C3N4)是一种被广泛用作光催化产氢的吸光材料,然而,纯g-C3N4的光生电子–空穴对会迅速重组,其光催化活性非常低.负载助催化剂能够有效抑制光生载流子的复合,是提高光催化产氢速率的有效方法.助催化剂的作用是将电子和空穴转移给相应的反应物,因此除了助催化剂和光吸收材料之间的能级匹配之外,助催化剂负载的位置也是非常重要的.通过常规方法制备的助催化剂一般是随机分布的,而光化学方法可以将助催化剂沉积在电子和空穴的出口处,从而有利于下一步的光催化反应.使用光化学沉积法,可以通过光化学氧化制备氧化型助催化剂,也可以通过光化学还原制备还原型助催化剂.光化学法是还原贵金属助催化剂的一种常用方法,但是对于制备非贵金属助催化剂来说,它仍然是一种相对新颖的方法.光化学法目前正处于发展阶段,依然缺乏成分调控的手段,因此我们致力于发展相对准确、可控的光沉积方法.H2PO2^–由于其特殊的性质被用于光化学还原过渡金属,然而,在H2PO2^–存在下形成的颗粒非常大且高度结晶,这可能抑制光催化剂的活性.本文设计了一种利用其他磷酸盐光沉积合成光催化剂的新方法,旨在制备可控的弱结晶和小尺寸的助催化剂,以提高产氢活性.首先以不同磷酸盐为原料制备催化剂,发现以H2PO3^–为无机牺牲剂制得的催化剂的光催化产氢活性非常突出,而且制得的催化剂具有无定形结构并且平均尺寸约为10 nm.通过XRD, XPS等多种表征,证实了该条件下得到的产物是Ni(OH)2/g-C3N4.同时,通过设计对照实验,发现在使用H2PO3^–作为牺牲剂, NiCl2作为镍源, g-C3N4作为光吸收材料条件下才能制得效果最好的催化剂.然后对光沉时间,原料添加量,产氢牺牲剂等多组条件进行了优化,得到最优的复合光催化剂Ni(OH)2/g-C3N4(4.36wt%)的光催化产氢速率为13707.86μmol·g^-1·h^-1,甚至高于Pt–4.36wt%/g-C3N4的活性(11210.93μmol·g^-1·h^-1).最后,通过PL, TR-PL, SPV, I-V等多种表征对反应机理进行探究,结果表明,光催化产氢性能提升主要原因是Ni(OH)2的负载可以有效提高光生电荷的分离和转移效率,抑制光生电子对的重组.     

激光闪光光解技术研究Pt4+掺杂提高TiO2光催化活性机制

通过用纳秒激光直接激发Pt⁴⁺掺杂的TiO₂透明溶胶体系,研究了440 nm处O^-吸收光谱的衰减过程.O^-是被捕获的正空穴的信号,是光催化反应过程中产生OH.自由基的决定影响因素.OH.浓度和衰减速度决定了光催化反应的效率.研究表明,O^-的寿命可以长达几十微秒.利用纳秒激光闪光光解的研究结果阐明了Pt⁴⁺掺杂显著提高TiO₂光催化活性的机制.     

Pt-MOx/CeO2水相重整催化剂上氧化物助剂对于水气变换反应的促进作用研究(英文)

甲醇水相重整是一种在相对温和条件下.的有效产氢路径。采用分步浸渍法制备Pt/CeO₂和Pt-MO_x/CeO₂(M=Fe、Cr、Mg、Mn)系列催化剂,并对其反应性能进行了研究。采用XPS、XRD、TEM、CO-TPD、NH₃-TPD、CO₂-TPD等表征手段对催化剂的金属价态、氧空位数量、金属粒子分布、CO吸附性能和催化剂的酸/碱性等性质进行表征和分析。通过关联结果表明,MO_x的加入削弱了Pt-CeO₂间的相互作用,促进了价态较低的Pt^δ+的生成,这有助于C-H键的裂解,促进甲醇的转化。Pt-MgO/CeO₂上的产氢量最高(164.78 mmol),CO和CH₄选择性相对较低,而Pt-CrO_x/CeO₂上的CH₄选择性最高(2.21%)_d对于Pt/CeO₃和Pt...     

无贵金属光催化剂VC/CdS纳米线将苯甲醇选择性氧化为苯甲醛并产氢

太阳能制氢作为一种绿色、实用、可再生的能源生产技术越来越受到人们的关注.传统的光解水产氢通常用三乙醇胺、硫化钠/亚硫酸钠、乳酸、甲醇、抗坏血酸和甲醇等做牺牲剂,这些试剂的加入不仅会污染环境,还会增加制氢成本.而目前完全无牺牲剂体系的产氢效率普遍较低,使得发展经济绿色的牺牲剂体系尤为迫切.通过光催化在单一水性体系中同时生产可储存和可再生的氢气与高附加值的有机化学品是一种新兴环保的策略.本文采用简单的静电自组装和煅烧方法将碳化钒(VC)和CdS纳米线(NW)复合形成VC/CS.结果表明,与原始的CdS NWs相比,负载适量VC的CdS NWs的光催化活性显著提高.然而,同时促进光解水产氢和苯甲醇选择性氧化的机理仍需要进一步探究.X射线衍射谱、高倍透射电子显微镜、扫描透射电子显微镜以及光电子能谱结果表明,VC和CdS NW是紧密结合的,且Cd,S,C和V元素均匀分布,由于两者之间的紧密结合引起了催化剂颜色变化.紫外可见光谱(UV-Vis)结果表明,样品的光吸收范围增大,但吸收带边没有发生明显改变.当采用Na₂S·9H₂O和Na₂SO₃做牺牲剂时,VC/CS的产氢活性明显高于Pt负载的CdS,说明VC是一种非常有利于产氢的非贵金属助催化剂.当改用苯甲醇(BO)做牺牲剂时,产氢速率明显增加,同时苯甲醇选择性氧化成苯甲醛(BD).进一步增加VC的负载量,样品产氢活性先增加后减小;当VC的负载量达到15%(VC/CS-15)时,在可见光(λ>420 nm)照射2 h后产氢效率达到20.5 mmol g^–1 h^–1,BO转化率为41%,BD选择性超过99%,约为CdS NW的661倍.将光活性测试时间由2 h延长至4 h,BO转化率由41%提高到58%,但BD选择性降至88%.样品VC/CS-15上BD和H₂生成趋势与UV-Vis漫反射光谱结果一致,表明反应是通过光催化过程进行的.此外,VC/CS-15在单色420 nm处产生BD和H₂的表观量子效率约为7.5%.光催化活性的增强是由于VC的加入降低了样品的Zeta电位,使其对BO具有更强的吸附作用,同时VC在CdS NWs上的牢固附着为质子还原提供了更多的活性位点,通过减少电荷传输距离和提供更宽的电子传输通道来增强光生电子的传输.综上,本文设计的同时产氢和生成高附加值有机化学品的方法光解水产氢提供了新思路.     

供体-受体型卟啉基金属有机框架实现有效电荷分离高效光催化析氢（英文）

利用光催化的方法将太阳能转化为氢能,是生产可持续燃料的有效途径之一.金属有机框架(MOFs)作为一类新兴的有机-无机杂化材料引起了研究者的广泛关注.由于MOFs材料的结构可调性,在框架中引入具有良好光吸收性能的基元,可以使MOFs在分子尺度有序排列的同时实现光催化析氢.单组分MOFs由于结构的相对有限性,存在电荷分离效率低的问题,而供体-受体(D-A)型双组分MOFs能够有效地促进电荷转移,同时电荷转移相互作用可以扩大光谱吸收范围,这些优良性能使之成为极具潜力的光催化剂.因此,寻找能够形成D-A结构的MOFs材料,实现高效光催化析氢仍然是一项亟需解决的科学问题.本文采用简单的溶剂热法将供体卟啉与受体二苯并噻吩砜(BTDO)相结合,构筑了一种卟啉基(TCPP)的D-A型MOF(TCPP-Zn-BTDO),其中, TCPP供体分子和BTDO受体分子通过Zn²⁺离子配位连接.红外吸收光谱中砜基的特征吸收峰以及电感耦合等离子体质谱表明有硫元素存在,说明成功引入了电子受体BTDO.TCPP-Zn-BTDO的光催化析氢效率较好,为1.48 mmolg^-1...     

卟啉修饰g-C3N4提高光催化产氢活性研究

半导体光催化制氢是一种可实现持续制备和储存氢气的绿色技术.石墨相氮化碳(g-C3N4)是研究广泛的光催化剂,但其仍存在光利用率低、光生电子和空穴易复合等问题,制约着光催化产氢的性能.利用给电子卟啉修饰g-C3N4,构建了四(4-羧基)苯基卟啉(TCPP)以共价/非共价方式修饰g-C3N4的催化剂.卟啉共价修饰g-C3N4(gC3N4-TCPP0.1)及非共价复合结构(TCPP0.1/g-C3N4)光催化产氢速率分别为6 997和5 399μmol·g-1·h-1,较g-C3N4分别提高了53%和18%. TCPPx/g-C3N4异质结加强了界面接触,促进了电荷转移,增强了可见光吸收能力,进而提高了光催化制氢性能. g-C3N4-TCPPx中, TCPP的接枝拓展了共轭结构,优化了电子结构,增大了分子偶极,促进了电荷分离,共价桥键为电荷传输提供了通道.     

Co（Ⅱ）-空穴和Pt-电子助催化剂协同作用增强P掺杂g-C3N4光催化产氢性能（英文）

石墨相氮化碳(g-C3N4)是一种新型的有机半导体材料,具有独特的层状结构、合适的能带位置、简单的制备方法以及出色的稳定性等特点,因而被广泛应用于光催化产氢领域.但是,较高的光生载流子的复合率和受限的迁移率大大地限制了g-C3N4的光催化产氢性能.目前,大量的研究证实块状g-C3N4的液相剥离、表面改性、元素掺杂、与其他半导体复合构筑异质结以及负载助催化剂等方法可以在一定程度上提高g-C3N4的光催化产氢性能.但是单一的g-C3N4改性方法往往并不能获得最理想的光催化产氢性能,因此,本文采用低温磷化法制备了二价钴(Co(II))修饰的磷(P)掺杂的g-C3N4纳米片(Co(II)/PCN),同时实现了掺杂P原子和负载空穴助催化剂Co(II),该催化剂表现出出色的光催化产氢性能.在光催化制氢过程中,铂(Pt)纳米颗粒作为电子助催化剂成功的负载在Co(II)/PCN上.光催化实验结果表明,最佳的Pt/Co(II)/PCN复合材料光催化产氢速率达到774μmol·g^?1·h^?1,比纯相的g-C3N4纳米片(89.2μmol·g^?1·h^?1)提升8.6倍.同时优化的光催化剂具有良好的光催化稳定性,并在402 nm处具有2.76%的量子产率.XRD,TEM,STEM-EDX和AFM结果证明,成功制备了纳米片状形貌的g-C3N4及其复合材料,催化剂中均匀的分布着Co和P元素.通过XPS证明了P-N的存在以及Co(II)的存在,并且Co(II)是以一种无定型的CoOOH的形式吸附在g-C3N4表面.光照后的TEM证明Pt颗粒成功的负载在Co(II)/PCN表面.UV-vis DRS表明,由于P的掺杂以及Co(II)的修饰,Co(II)/PCN相比于g-C3N4纳米片在可见光区域光吸收有了明显的增强.通过稳态和瞬态光致发光光谱分析,同时结合电化学分析表征(i-t、EIS)以及电子顺磁共振技术分析,证实了Co(II)/PCN高效光催化性能的原因可能是由于更高效的光生载流子分离效率.本文对Pt/Co(II)/PCN可能的光催化增强机理提出了设想.P的掺杂可以优化g-C3N4的电子结构,提高其光生载流子分离效率.而以Pt作为电子助催化剂,可以有效地捕获P掺杂的g-C3N4导带中的光生电子,进而发生水还原产氢反应;以Co(II)作为空穴助催化剂,可以捕获价带中的光生空穴,进而发生三乙醇胺氧化反应.通过采用不同功能的助催化剂,实现P掺杂g-C3N4光生电子空穴的定向分流,促进了P掺杂g-C3N4的光生载流子的分离,从而提高催化剂的光催化产氢性能.本文可以为设计具有空穴-电子双助催化剂的光催化产氢系统提供一个新的思路.     

Photocatalytic hydrogen evolution from carbon-neutral oxalate with 2-phenyl-4-(1-naphthyl)quinolinium ion and metal nanoparticles

Photocatalytic hydrogen evolution has been made possible by using oxalate as a carbon-neutral electron source, metal nanoparticles as hydrogen-evolution catalysts and the 2-phenyl-4-(1-naphthyl)quinolinium ion (QuPh(+)-NA), which forms the long-lived electron-transfer state upon photoexcitation, as a photocatalyst. The hydrogen evolution was conducted in a deaerated mixed solution of an aqueous buffer and acetonitrile (MeCN) [1:1 (v/v)] by photoirradiation (λ > 340 nm). The gas evolved during the photocatalytic reaction contained H(2) and CO(2) in a molar ratio of 1:2, indicating that oxalate acts as a two-electron donor. The hydrogen yield based on the amount of oxalate reached more than 80% under pH conditions higher than 6. Ni and Ru nanoparticles as well as Pt nanoparticles act as efficient hydrogen-evolution catalysts in the photocatalytic hydrogen evolution. The photocatalyst for hydrogen evolution can be used several times without significant deactivation of the catalytic activity. Nanosecond laser flash photolysis measurements have revealed that electron transfer from oxalate to the photogenerated QuPh˙-NA˙(+), which forms a π-dimer radical cation with QuPh(+)-NA [(QuPh˙-NA˙(+))(QuPh(+)-NA)], occurs followed by subsequent electron transfer from QuPh˙-NA to the hydrogen-evolution catalyst in the photocatalytic hydrogen evolution. Oxalate acts as an efficient electron source under a wide range of reaction conditions.     

Ultrafast charge separation and long-lived charge separated state in photocatalytic CdS-Pt nanorod heterostructures

Colloidal semiconductor-metal nanoheterostructures that combine the light-harvesting ability of semiconductor nanocrystals with the catalytic activity of small metal nanoparticles show promising applications for photocatalysis, including light-driven H(2) production. The exciton in the semiconductor domain can be quenched by electron-, hole-, and energy transfer to the metal particle, and the competition between these processes determines the photocatalytic efficiency of these materials. Using ultrafast transient absorption spectroscopy, we show that, in CdS-Pt heterostructures consisting of a CdS nanorod with a Pt nanoparticle at one end, the excitons in the CdS domain dissociate by ultrafast electron transfer (with a half-life of ～3.4 ps) to the Pt. The charge separated state is surprisingly long-lived (with a half-life of ～1.2 ± 0.6 μs) due to the trapping of holes in CdS. The asymmetry in the charge separation and recombination times is believed to be the key feature that enables the accumulation of the transferred electrons in the Pt tip and photocatalysis in the presence of sacrificial hole acceptors.     

PHOTOCATALYTIC HYDROGEN EVOLUTION FROM WATER SPLITTING UNDER VISIBLE LIGHT IRRADIATION ON NOVEL PHOTOCATALYST FULLENES-PVP-ZN_(0.999)NI(0.001)S

1. INTRODUCTION1. INTRODUCTIONOne of the most widely discussed subjects these days is the energy crisis, i.e. the oil shortage and the oil price rising, which encouraged us to research and develop new green energy-hydrogen energy in the 21st century. Therefore, hydrogen produced from water splittingwith photocatalyst has been extensively studied from the viewpoint of photo energy, such as solar energy conversion to chemical and electricity energy, and environmental concerns. To date, …     

PHOTOCATALYTIC HYDROGEN EVOLUTION FROM WATER SPLITTING UNDER VISIBLE LIGHT IRRADIATION ON NOVEL PHOTOCATALYST FULLENES-PVP-ZN0.999NI0.001S

Fullerenes (C60/C70) linked up to Ni-doped ZnS through the medium of an amphalic polymer polyvinyl pyrrolidone (PVP) to form a new kind of photocatalyst for hydrogen evolution from aqueous Na2S/Na2SO3 solution under visible light irradiation, the photocatalytic activities of this novel photocatalyst C60/C70-PVP-Zn0.999Ni0.001S are 3-5 fold higher compared with that of precurse catalyst Zn0.999Ni0.001S. This result could be attributed to Schottky barrier layer built between C60/C70 and Zn0.999Ni0.001S due to the electro-negativity of C60 and characteristic of being used as a multiple electron acceptor. C60 or C60/C70, its moiety, with its low energy first excited singlet state, is a good energy acceptor and in addition readily accepts multiple electrons, making it a potential electron accumulate as we know, which could protect the separation between electrons and holes against combination. This is an important reason for the marked increase of amount of H2 evolution during the photocatalytic process for the composite system C60/C70-PVP-Zn0.999Ni0.001S.     

Exfoliated and reorganized graphite oxide on titania nanoparticles as an auxiliary co-catalyst for photocatalytic solar conversion

The hybrid of graphite oxide (GO)/TiO(2) was prepared through the spontaneous exfoliation of bulky graphite oxide and reorganization with TiO(2) nanoparticles as a solar conversion and hydrogen-generating photocatalyst. GO/TiO(2) showed enhanced activities for both photocurrent generation (in an electrode form) and hydrogen production (in a slurry form) than those of bare TiO(2) under UV light irradiation. The enhanced photocatalytic activity of GO/TiO(2) is ascribed to the ability of graphitic layers in accepting and transporting electrons from excited TiO(2), promoting the charge separation. When GO was hybridized with platinized TiO(2) (Pt/TiO(2)), it showed a marked synergistic effect for the photocatalytic hydrogen production compared with GO/TiO(2) and Pt/TiO(2). This indicates that the cheap and abundant carbon material can be a good candidate for an electron attracting reservoir and an auxiliary co-catalyst for the photocatalytic hydrogen production.     

Photocatalytic hydrogen evolution based on efficient energy and electron transfers in donor-bridge-acceptor multibranched-porphyrin-functionalized platinum nanocomposites

Two donor-bridge-acceptor conjugates (5,10,15,20-tetrakis[4-(N,N-diphenylaminobenzoate)phenyl] porphyrin (TPPZ) and 5,10,15,20-tetrakis[4-(N,N-diphenylaminostyryl)phenyl] porphyrin (TPPX)) were covalently linked to triphenylamine (TPA) at the meso-position of porphyrin ring. The triphenylamine entities were expected to act as energy donors and the porphyrins to act as an energy acceptor. In this paper, we report on the synthesis of these multibranched-porphyrin-functionalized Pt nanocomposites. The conjugates used here not only served as a stabilizer to prevent agglomeration of Pt nanoparticles, but also as a light-harvesting photosensitizer. The occurrence of photoinduced electron-transfer processes was confirmed by time-resolved fluorescence and photoelectrochemical spectral measurements. The different efficiencies for energy and electron transfer in the two multibranched porphyrins and the functionalized Pt nanocomposites were attributed to diverse covalent linkages. Moreover, in the reduction of water to produce H(2), the photocatalytic activity of the Pt nanocomposite functionalized by TPPX, in which the triphenylamine and porphyrin moieties are bonded through an ethylene bridge, was much higher than that of the platinum nanocomposite functionalized by TPPZ, in which the two moieties are bonded through an ester. This investigation demonstrates the fundamental advantages of constructing donor-bridge-acceptor conjugates as highly efficient photosensitizers based on efficient energy and electron transfer.     

Reduced graphene oxide as capturer of dyes and electrons during photocatalysis: surface wrapping and capture promoted efficiency

To elucidate the roles of graphene in photoelectric events and mass transfer during photocatalytic process is important for engineering graphene-semiconductor hybrid photocatalyst. Here, we demonstrated reduced graphene oxide (RGO) capturing dyes and photoinduced electrons during photocatalytic degradation of organic dyes in water. It captures dyes from water through adsorption and desorption irreversible hysteresis, and captures photoinduced electrons from semiconductor through surface junction. The RGO was attached to the surface of TiO(2) in the form of surface wrapping. After one-step photocatalytic reduction of graphene oxide (GO) and TiO(2) in ethanol-water solvent under UV irradiation, the RGO wrapped TiO(2) hybrid (graphene-w-TiO(2)) photocatalyst was obtained. Using visible absorption spectroscopy, we also demonstrated these captured dyes were degraded during photocatalysis. The photocatalytic test showed the RGO significantly improved the photocatalytic activity of this hybrid photocatalyst.     

In‐situ Platinum Plasmon Resonance Effect Prompt Titanium Dioxide Nanocube Photocatalytic Hydrogen Evolution

Herein, Pt‐decorated TiO₂ nanocube hierarchy structure (Pt‐TNCB) was fabricated by a facile solvothermal synthesis and in‐situ photodeposition strategy. The Pt‐TNCB exhibits an excellent solar‐driven photocatalytic hydrogen evolution rate (337.84 μmol h^?1), which is about 37 times higher than that of TNCB (9.19 μmol h^?1). Interestingly, its photocatalytic property is still superior to TNCB with post modification Pt (1 wt %) (208.11 μmol h^?1). The introduction of Pt efficiently extends the photoresponse of the composite material from UV to visible light region, simultaneously boosting their solar‐driven photocatalytic performance, which attribute to the porous structure, the sub size TNCB, the SPR effect of Pt NPs and strong interaction of two components. In fact, Pt NPs can enhance collective oscillations on delocalized electrons, which is conducive to capture electrons and hinder the recombination of photogenerated electron‐hole pairs, leading to the longer lifetime of photogenerated charges. The fabrication of Pt‐TNCB photocatalyst with SPR effect may provide a promising method to improve visible‐light photocatalytic activities for traditional photocatalysts.     

Engineering the Atomic Interface with Single Platinum Atoms for Enhanced Photocatalytic Hydrogen Production

It is highly desirable but challenging to optimize the structure of photocatalysts at the atomic scale to facilitate the separation of electron–hole pairs for enhanced performance. Now, a highly efficient photocatalyst is formed by assembling single Pt atoms on a defective TiO₂ support (Pt₁/def‐TiO₂). Apart from being proton reduction sites, single Pt atoms promote the neighboring TiO₂ units to generate surface oxygen vacancies and form a Pt‐O‐Ti³⁺ atomic interface. Experimental results and density functional theory calculations demonstrate that the Pt‐O‐Ti³⁺ atomic interface effectively facilitates photogenerated electrons to transfer from Ti³⁺ defective sites to single Pt atoms, thereby enhancing the separation of electron–hole pairs. This unique structure makes Pt₁/def‐TiO₂ exhibit a record‐level photocatalytic hydrogen production performance with an unexpectedly high turnover frequency of 51423 h^?1, exceeding the Pt nanoparticle supported TiO₂ catalyst by a factor of 591.