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A high‐nuclearity titanium‐oxide cluster (TOC), Ti31O52(OiPr)4Bz24 (denoted as Ti31; Bz=PhCO2), was synthesized via a seed‐mediated synthesis method during the solvothermal reaction of the super‐Keggin cluster Ti17O24(OiPr)20 (denoted as Ti17) and Ti(OiPr)4. Single‐crystal X‐ray diffraction analyses indicate that Ti17 acts as a template for the addition of two Ti7O6 rings to form Ti31. The optical absorption edge of Ti31 slightly shifts to 446 nm, relative to the 419 nm absorption edge of Ti17. Ti31 has much better visible‐light response and charge‐separation properties than Ti17, as confirmed by electrochemical impedance, photoluminescence spectroscopy, and transient photocurrent response. Ti31 also shows much better activity and stability than Ti17 in the solar synthesis of cyclocarbonate through CO2/epoxide cycloaddition. This study not only provides a high‐nuclearity member of the TOC family, but also suggests a potential method to enhance the photocatalytic activity of the known TOCs for more efficient solar energy harvesting. [ABSTRACT FROM AUTHOR]

A cryptand-like Ti-coordination compound, namely Ti12Cs, comprising two Ti6-salicylate cages and hosting two Cs+ ions, was synthesized by the solvothermal method. It exhibits strong visible-light absorption with an absorption band edge of 652 nm, attributed to the electron transition from salicylate ligands to Ti ions. Electrochemical impedance, visible-light transient photocurrent response, and photoluminescence spectra confirm that Ti12Cs has excellent visible-light response and charge-separation properties. Ti12Cs can be used as a heterogeneous and recyclable photocatalyst for CO2/epoxide cycloaddition, with high utilization efficiency of visible-light under mild conditions. The mechanism investigation points to a synergistic effect of photocatalysis and Lewis acid catalysis. [ABSTRACT FROM AUTHOR]

Graphdiyne (GDY) with a direct band gap, excellent carrier mobility and uniform pores, is regarded as a promising photocatalytic material for solar energy conversion, while the research on GDY in photocatalysis is a less developed field. Herein, the distinctive structure, adjustable band gap, and electronic properties of GDY for photocatalysis is firstly summarized. The construction and progress of GDY‐based photocatalysts for solar energy conversion, including H2 evolution reaction (HER), CO2 reduction reaction (CO2RR) and N2 reduction reaction (NRR) are then elaborated. At last, the challenges and perspectives in developing GDY‐based photocatalysts for solar fuel production are discussed. It is anticipated that a timely Minireview will be helpful for rapid progress of GDY in solar energy conversion. [ABSTRACT FROM AUTHOR]

Represented herein is the first example of N‐radical generation direct from N−H bond activation under mild and redox‐neutral conditions. The in situ generated N‐radical intercepts a reduced heteroarylnitrile/aryl halide for C−N bond formation under visible‐light irradiation of quantum dots (QDs). A series of aryl and alkylamines with heteroarylnitriles/aryl halides exhibit high efficiency, site‐selectivity and good functional‐group tolerance. Moreover, consecutive C−C and C−N bond formation using benzylamines as substrates is also achieved, producing N‐aryl‐1,2‐diamines with H2 evolution. The redox‐neutral conditions, broad substrate scope, and efficiency of N‐radical formation are advantageous for organic synthesis. [ABSTRACT FROM AUTHOR]

A new way to form fluorenones via the direct excitation of substrates instead of photocatalyst to activate the C(sp2)−H bond under redox‐neutral condition is reported. Our design relies on the photoexcited aromatic aldehyde intermediates that can be intercepted by cobaloxime catalyst through single electron transfer for following β‐H elimination. The generation of acyl radical and successful interception by a metal catalyst cobaloxime avoid the use of a photocatalyst and stoichiometric external oxidants, affording a series of highly substituted fluorenones, including six‐membered ketones, such as xanthone and thioxanthone derivatives in good to excellent yields, and with hydrogen as the only byproduct. This catalytic system features a readily available metal catalyst, mild reaction conditions and broad substrate scope, in which sunlight reaction and scale‐up experiments by continuous‐flow approach make the new methodology sustainable and amenable for potentially operational procedures. [ABSTRACT FROM AUTHOR]

A direct strategy for the difunctionalization of alkenes, with acylation occurring at the more substituted alkene position, would be attractive for complex ketone synthesis. We report herein a reaction driven by a single photocatalyst that enables α‐acylation in this way with the introduction of a fluoromethyl, alkyl, sulfonyl or thioether group at the β‐position of the alkene with high chemo‐ and regioselectivity under extremely mild conditions. Crucial to the success of this method are rate differences in the kinetics of radical generation through single‐electron transfer (SET) between different radical precursors and the excited photocatalyst (PC*). Thus, the β‐position of the alkene is first occupied by the group derived from the radical precursor that can be generated most readily, and α‐keto acids could be used as an electrophilic reagent for the α‐acylation of alkenes. [ABSTRACT FROM AUTHOR]

Herein, cobaloxime is used for the first time as a catalyst for the synthesis of phosphorylated heteroaromatics, which is an intriguing and versatile functional motif. With visible‐light irradiation, cobaloxime not only oxidizes phosphine oxides to form phosphorus radicals (P‐radicals) for a subsequent reaction with radical acceptor isocyanides or heteroaromatics, but also combines the radical intermediate with β‐H elimination, thereby producing phosphorylated heteroaromatics with only H2 or CH4 as byproduct. Phosphine oxides with dialkyl, alkylaryl, and diaryl substituents could be directly transformed into phosphorylated phenanthridines, benzothiazoles, isoquinolines, and common heteroaromatics. This catalytic system features extremely mild conditions, broad substrate scope and good to excellent yields. Scale‐up reaction and sunlight reaction show the great application potential in the green synthesis of important organophosphorus chemicals. [ABSTRACT FROM AUTHOR]

As one of the most ubiquitous bulk reagents available, the intrinsic chemical inertness of tetrahydrofuran (THF) makes direct and site‐selective C(sp3)−H bond activation difficult, especially under redox neutral condition. Here, we demonstrate that semiconductor quantum dots (QDs) can activate α‐C−H bond of THF via forming QDs/THF conjugates. Under visible light irradiation, the resultant alkoxyalkyl radical directly engages in radical cross‐coupling with α‐amino radical from amino C−H bonds or radical addition with alkene or phenylacetylene, respectively. In contrast to stoichiometric oxidant or hydrogen atom transfer reagents required in previous studies, the scalable benchtop approach can execute α‐C−H bond activation of THF only by a QD photocatalyst under redox‐neutral condition, thus providing a broad of value added chemicals starting from bulk THFs reagent. [ABSTRACT FROM AUTHOR]

1,4‐Dicarbonyl compounds are intriguing motifs and versatile precursors in numerous pharmaceutical molecules and bioactive natural compounds. Direct incorporation of two carbonyl groups into a double bond at both ends is straightforward, but also challenging. Represented herein is the first example of 1,2‐dicarbonylation of alkenes by photocatalysis. Key to success is that N(n‐Bu)4+ not only associates with the alkyl anion to avoid protonation, but also activates the α‐keto acid to undergo electrophilic addition. The α‐keto acid is employed both for acyl generation and electrophilic addition. By tuning the reductive and electrophilic ability of the acyl precursor, unsymmetric 1,4‐dicarbonylation is achieved for the first time. This metal‐free, redox‐neutral and regioselective 1,2‐dicarbonylation of alkenes is executed by a photocatalyst for versatile substrates under extremely mild conditions and shows great potential in biomolecular and drug molecular derivatization. [ABSTRACT FROM AUTHOR]

A bis(pyridyl)amine‐bipyridine‐iron(II) framework (Fe(BPAbipy)) of complexes 1–3 is reported to shed light on the multistep nature of CO2 reduction. Herein, photocatalytic conversion of CO2 to CO even at low CO2 concentration (1 %), together with detailed mechanistic study and DFT calculations, reveal that 1 first undergoes two sequential one‐electron transfer affording an intermediate with electron density on both Fe and ligand for CO2 binding over proton. The following 2 H+‐assisted Fe‐CO formation is rate‐determining for selective CO2‐to‐CO reduction. A pendant, proton‐shuttling α‐OH group (2) initiates PCET for predominant H2 evolution, while an α‐OMe group (3) cancels the selectivity control for either CO or H2. The near‐unity selectivity of 1 and 2 enables self‐sorting syngas production at flexible CO/H2 ratios. The unprecedented results from one kind of molecular catalyst skeleton encourage insight into the beauty of advanced multi‐electron and multi‐proton transfer processes for robust CO2RR by photocatalysis. [ABSTRACT FROM AUTHOR]

Inspired by the natural [NiFe]‐H2ase, we designed mimic 1, (dppe)Ni(μ‐pdt)(μ‐Cl)Ru(CO)2Cl to realize effective H2 evolution under photocatalytic conditions. However, a new species 2 was captured in the course of photo‐, electro‐, and chemo‐ one‐electron reduction. Experimental studies of in situ IR spectroscopy, EPR, NMR, X‐ray absorption spectroscopy, and DFT calculations corroborated a dimeric structure of 2 as a closed‐shell, symmetric structure with a RuI center. The isolated dimer 2 showed the real catalytic role in photocatalysis with a benchmark turnover frequency (TOF) of 1936 h−1 for H2 evolution, while mimic 1 worked as a pre‐catalyst and evolved H2 only after being reduced to 2. The remarkably catalytic activity and unique dimer structure of 2 operated in photocatalysis unveiled a broad research prospect in hydrogenases mimics for advanced H2 evolution. [ABSTRACT FROM AUTHOR]

A photoredox benzyl activation was developed via formidable C(sp3)–C(sp3) bond dissociation of 1‐aryl acetone oxime esters, which were easily prepared from benzyl ketones. Further coupling with O‐ and N‐ nucleophiles successfully forged important benzyl ether and amines derivatives in one pot. In this process, different substitutions on oxime esters were found compatible and various primary and secondary alcohols and amines, as well as amides showed good performance as nucleophiles. Mechanistic studies by control experiments, electrochemical measurements and in‐situ NMR spectra proposed a N–O bond interruption/C–C bond fragmentation/oxidation sequence to provide the key cation intermediate for the next electrophilic SN process. The features of mild condition, short reaction time and broad substrate scope made this new strategy much promising in the transformation of benzyl compounds, which might be valuable in last‐stage functionalizations. [ABSTRACT FROM AUTHOR]

The photocatalytic reduction of nitrogen (N2) with water (H2O) as the reducing agent holds great promise as a sustainable future technology for the synthesis of ammonia (NH3). Herein, the effect of oxygen vacancies and electron‐rich Cuδ+ on the performance of zinc‐aluminium layered double hydroxide (ZnAl‐LDH) nanosheet photocatalysts for N2 reduction to NH3 under UV–vis excitation is systematically explored. Results show that a 0.5%‐ZnAl‐LDH nanosheet photocatalyst (containing 0.5 mol% Cu by metal basis) affords a remarkable NH3 production rate of 110 µmol g−1 h−1 and excellent stability in pure water. The X‐ray absorption spectroscopy, electron paramagnetic resonance, and density functional theory calculations reveal that Cu addition imparts oxygen vacancies and coordinatively unsaturated Cuδ+ (δ < 2) with electron‐rich property in the ZnAl‐LDH nanosheets, both of which readily contribute to efficient separation and transfer of photogenerated electrons and holes and promote N2 adsorption, thereby both activating N2 and facilitating its multielectrons reduction to NH3. [ABSTRACT FROM AUTHOR]

Catalytic C1 chemistry based on the activation/conversion of synthesis gas (CO+H2), methane, carbon dioxide, and methanol offers great potential for the sustainable development of hydrocarbon fuels to replace oil, coal, and natural gas. Traditional thermal catalytic processes used for C1 transformations require high temperatures and pressures, thereby carrying a significant carbon footprint. In comparison, solar‐driven C1 catalysis offers a greener and more sustainable pathway for manufacturing fuels and other commodity chemicals, although conversion efficiencies are currently too low to justify industry investment. In this Review, we highlight recent advances and milestones in light‐driven C1 chemistry, including solar Fischer–Tropsch synthesis, the water‐gas‐shift reaction, CO2 hydrogenation, as well as methane and methanol conversion reactions. Particular emphasis is placed on the rational design of catalysts, structure–reactivity relationships, as well as reaction mechanisms. Strategies for scaling up solar‐driven C1 processes are also discussed. [ABSTRACT FROM AUTHOR]

A simple one-step thermal polymerization method was developed for synthesis of holey graphitic carbon nitride nanotubes, involving direct heating of mixtures of melamine and urea or melamine and cyanuric acid in specific mass ratios. Supramolecular structures formed between the precursor molecules guided nanotube formation. The porous and nanotubular structure of the nanotubes facilitated efficient charge carrier migration and separation, thereby enhancing photocatalytic H2 production in 20 vol.% lactic acid under visible light irradiation. Nanotubes synthesized using melamine and urea in a 1:10 mass ratio (denoted herein as CN-MU nanotubes) exhibited a photocatalytic hydrogen production rate of 1,073.6 μmol·h−1·g−1 with Pt as the cocatalyst, a rate of 4.7 and 3.1 times higher than traditional Pt/g-C3N4 photocatalysts prepared from graphitic carbon nitride (g-C3N4) obtained by direct thermal polymerization of melamine or urea, respectively. On the basis of their outstanding performance for photocatalytic H2 production, it is envisaged that the holey g-C3N4 nanotubes will find widespread uptake in other areas, including photocatalytic CO2 reduction, dye-sensitized solar cells and photoelectrochemical sensors. [ABSTRACT FROM AUTHOR]

Light‐driven multielectron redox reactions (e.g. hydrogen (H2) evolution, CO2 reduction) have recently appeared at the front of solar‐to‐fuel conversion. In this Minireview, we focus on the recent advances in establishing semiconductor quantum dot (QD) assemblies to enhance the efficiencies of these light‐driven multielectron reduction reactions. Four models of QD assembly are established to promote the sluggish kinetics of multielectron transfer from QDs to cocatalysts, thus leading to an enhanced activity of solar H2 evolution or CO2 reduction. We also forecast the potential applications of QD assemblies in other multielectron redox reactions, such as nitrogen (N2) fixation and oxygen (O2) evolution from H2O. [ABSTRACT FROM AUTHOR]

We describe a cobalt(III) complex bearing a phosphinoamine ligand, [Cp*Co(1,2‐Ph2PC6H4NH2)(Cl)]Cl (1), as a proton reduction catalyst which is not only electrochemically active but also delivers good photocatalytic performance. In a system containing semiconductor quantum dots (QDs) and ascorbic acid, complex 1 achieves proton reduction, producing H2 with a turnover number >10000 and an apparent quantum yield of 5.51 % at 450 nm. The important role of the nitrogen basic site in the cobalt first coordination sphere is demonstrated by the difference in the reactivity of two cobalt complexes 1 and [Cp*Co(1,2‐Ph2PC6H4N(Me)2)(Cl)]Cl (2), in which the latter, with a tertiary amine leads to a lower turnover number of circa 6000 for proton reduction. [ABSTRACT FROM AUTHOR]

Abstract: Colloidal semiconductor quantum dots (QDs) have recently attracted widespread interest for diverse applications. Owing to their quantum confinement effects, rich surface binding properties, high surface‐to‐volume ratios, broad and intense absorption spectra in the visible region, and low cost as well, QDs offer new and versatile ways to serve as photocatalysts for organic synthesis. Most recently, the use of QDs photocatalysts is springing up in organic synthesis. Herein, we highlight the recent advances of QDs used for smart and clean organic transformations. [ABSTRACT FROM AUTHOR]

Unlike their bulk counterpart, CuxInyS quantum dots (QDs) prepared by an aqueous synthetic approach, show promising activity for photocatalytic hydrogen evolution, which is competitive with the state-of-the-art Cd chalcogen QDs. Moreover, the as-prepared CuxInyS QDs with In-rich composition show much better efficiency than the stoichiometric ones (Cu/In=1:1). [ABSTRACT FROM AUTHOR]

[2+2] Photocycloaddition, for example, the dimerization of chalcones and cinnamic acid derivatives, is a unique strategy to construct cyclobutanes, which are building blocks for a variety of biologically active molecules and natural products. However, most attempts at the above [2+2] addition have focused on solid-state, molten-state, or host-guest systems under ultraviolet-light irradiation in order to overcome the competition of facile geometric isomerization of nonrigid olefins. We report a general and simple method to realize the intermolecular [2+2] dimerization reaction of these acyclic olefins to construct cyclobutanes in a highly regio- and diastereoselective manner in solution under visible light, which provides an efficient solution to a long-standing problem. [ABSTRACT FROM AUTHOR]

A facile and efficient one-pot reaction for the aerobic oxidative synthesis of 2-substituted quinazolines using visible-light catalysis has been developed. A variety of substituted aldehydes and 2-aminobenzylamines are amenable to producing the corresponding quinazolines in good to excellent yields under metal-free conditions. Electron paramagnetic resonance (EPR) measurements provide clear evidence on the formation of a superoxide radical anion (O2 ⋅−), which is responsible for this transformation. [ABSTRACT FROM AUTHOR]

Selective oxidation of alcohols to aldehydes/ketones has been achieved with the help of 3-mercaptopropionic acid (MPA)-capped CdSe quantum dot (MPA-CdSe QD) and visible light. Visible-light-prompted electron-transfer reaction initiates the oxidation. The thiyl radical generated from the thiolate anion adsorbed on a CdSe QD plays a key role by abstracting the hydrogen atom from the C−H bond of the alcohol (R1CH(OH)R2). The reaction shows high efficiency, good functional group tolerance, and high site-selectivity in polyhydroxy compounds. The generality and selectivity reported here offer a new opportunity for further applications of QDs in organic transformations. [ABSTRACT FROM AUTHOR]

A facile and green process was developed for the synthesis of pyrochlore H4Nb2O7 hollow microspheres by using hydrothermal treatment of Sn2Nb2O7 hollow microspheres in aqueous 2m HCl at 100-180°C. The facile transformation of Sn2Nb2O7 into H4Nb2O7 is facilitated by the intrinsic ion-exchange capability of Sn2Nb2O7. The resulting H4Nb2O7 hollow microspheres (diameter 1-2μm, shell thickness 100-200nm) displayed excellent photocatalytic performance for overall water splitting under UV irradiation, affording H2 and O2 evolution rates of 240 and 116μmolh-1g-1, respectively. Following decoration with 0.5wt% Pt, the H4Nb2O7 hollow microspheres demonstrated remarkably high H2 and O2 evolution rates of 1240 and 600μmolh-1g-1, respectively. To our knowledge, this work is the first reported study examining the photocatalytic performance of H4Nb2O7 for water splitting. The hydrothermal synthesis method described here is also applicable to the synthesis of pyrochlore H4Ta2O7 from Sn2Ta2O7, highlighting the versatility of the approach. [ABSTRACT FROM AUTHOR]

Metallic nickel nanostructures that were partially decorated by discrete nickel oxide layers were fabricated by in situ reduction of calcinated Ni-containing layered double hydroxide nanosheets, the structure of which was confirmed by extended X-ray absorption fine structure spectroscopy, X-ray photoelectron spectroscopy, and transmission electron microscopy. The existence of the abundant interfaces between the surface Ni oxide overlayer and metallic Ni altered the geometric/electronic structure of the Ni nanoparticles, making them apt for CO activation under light irradiation. Most importantly, the unique structure favors the C−C coupling reaction on its surface, which confers the catalyst unexpected reaction power towards higher hydrocarbons at moderate reaction conditions. This study leads to a green and sustainable approach for the photocatalytic production of highly valuable chemical fuels. [ABSTRACT FROM AUTHOR]

CdS nanoparticle‐decorated Cd nanosheets (CdS NP/Cd NSs) are successfully ­fabricated for the first time via a facile oxidation–sulfurization treatment of Cd nanosheets. Due to the high electrical conductivity and visible light reflectivity of Cd nanosheets, the obtained CdS NP/Cd NSs heterostructures show significantly enhanced activities for visible light‐driven photocatalytic H2 production compared to other reference CdS photocatalysts. [ABSTRACT FROM AUTHOR]

A novel K2Nb2O6 photocatalyst with pyrochlore structure has been synthesized via a facile one-pot hydrothermal route with no aid of additives. The as-prepared samples were characterized by powder X-ray diffraction, ultraviolet-visible spectroscopy and field emission scanning electron microscopy. The photocatalytic H2 evolution was performed in an aqueous methanol solution under UV light irradiation. The as-prepared K2Nb2O6 photocatalyst with pyrochlore structure showed higher H2 production activity than that of perovskite KNbO3 and commercial Nb2O5 powders in the absence of cocatalysts, due mainly to its unique crystal and energy band structures. The rate of H2 evolution can be significantly enhanced by loading of Pt nanoparticles. The highest H2 evolution rate of 121 µmol/h was reached when 0.7 wt% Pt nanoparticles were used, which was about 20 times higher than that of pristine K2Nb2O6. [ABSTRACT FROM AUTHOR]

Natural photosynthesis offers the concept of storing sunlight in chemical form as hydrogen (H2), using biomass and water. Herein we describe a robust artificial photocatalyst, nickel-hybrid CdS quantum dots (Nih-CdS QDs) made in situ from nickel salts and CdS QDs stabilized by 3-mercaptopropionic acid, for visible-light-driven H2 evolution from glycerol and water. With visible light irradiation for 20 h, 403.2 μmol of H2 was obtained with a high H2 evolution rate of approximately 74.6 μmol h−1 mg−1 and a high turnover number of 38 405 compared to MPA-CdS QDs (mercaptopropionic-acid-stabilized CdS quantum dots). Compared to CdTe QDs and CdSe QDs, the modified CdS QDs show the greatest affinity toward Ni2+ ions and the highest activity for H2 evolution. X-ray photoelectron spectroscopy (XPS), inductively-coupled plasma atomic emission spectrometry (ICP-AES), and photophysical studies reveal the chemical nature of the Nih-CdS QDs. Electron paramagnetic resonance (EPR) and terephthalate fluorescence measurements clearly demonstrate water splitting to generate ⋅OH radicals. The detection of DMPO-H and DMPO-C radicals adduct in EPR also indicate that ⋅H radicals and ⋅C radicals are the active species in the catalytic cycle. [ABSTRACT FROM AUTHOR]

Quantum dots (QDs) offer new and versatile ways to harvest light energy. However, there are few examples involving the utilization of QDs in organic synthesis. Visible-light irradiation of CdSe QDs was found to result in virtually quantitative coupling of a variety of thiols to give disulfides and H2 without the need for sacrificial reagents or external oxidants. The addition of small amounts of nickel(II) salts dramatically improved the efficiency and conversion through facilitating the formation of hydrogen atoms, thereby leading to faster regeneration of the ground-state QDs. Mechanistic studies reveal that the coupling reaction occurs on the QD surfaces rather than in solution and offer a blueprint for how these QDs may be used in other photocatalytic applications. Because no sacrificial agent or oxidant is necessary and the catalyst is reusable, this method may be useful for the formation of disulfide bonds in proteins as well as in other systems sensitive to the presence of oxidants. [ABSTRACT FROM AUTHOR]

Light, polymer, action: A set of water‐soluble poly(acrylic acid) catalysts PAA‐g‐Fe2S2 containing {Fe2S2}, an [FeFe]‐hydrogenase active‐site mimic, is synthesized. This system, combined with CdSe quantum dots and ascorbic acid, has an exceptional turnover number and initial turnover frequency (27 135 and 3.6 s−1) for the photocatalytic production of H2 in water, which is the highest efficiency to date for [FeFe]‐hydrogenase mimics. [ABSTRACT FROM AUTHOR]

The enzyme nitrogenase inspires the development of novel photocatalytic and electrocatalytic systems that can drive nitrogen reduction with water under similar low‐temperature and low‐pressure conditions. While photocatalytic and electrocatalytic N2 fixation are emerging as hot new areas of fundamental and applied research, serious concerns exist regarding the accuracy of current methods used for ammonia detection and quantification. In most studies, the ammonia yields are low and little consideration is given to the effect of interferants on NH3 quantification. As a result, NH3 yields reported in many works may be exaggerated and erroneous. Herein, the advantages and limitations of the various methods commonly used for NH3 quantification in solution (Nessler's reagent method, indophenol blue method, and ion chromatography method) are systematically explored, placing particular emphasis on the effect of interferants on each quantification method. Based on the data presented, guidelines are suggested for responsible quantification of ammonia in photocatalysis and electrocatalysis. [ABSTRACT FROM AUTHOR]

In article number 1501241, Tierui Zhang and co‐workers report that Cd nanosheets acting as a novel conductive support have been successfully developed to promote the photocatalytic H2 evolution of CdS nanoparticles grown in‐situ in nanosheets. The significantly enhanced photocatalytic activity is mainly attributed to the much higher electrical conductivity and optical reflectivity of Cd nanosheets compared to conventional conductive supports like carbon nanotubes or reduced graphene oxide. [ABSTRACT FROM AUTHOR]

The inside cover shows a cheap, simple, and efficient artificial photocatalyst, nickel‐hybrid CdS quantum dots (Nih‐CdS QDs), developed by Wu et al. for conversion of glycerol to H2 under visible light irradiation. The photocatalyst, formed in situ from 3‐mercaptopropionic acid‐CdS quantum dots and Ni2+ ions, is capable of producing H2 at pH values ranging from 5 to 9, and shows the highest photocatalytic activity known to date for H2 evolution from the relatively inert biomass glycerol, which has a low market price, in aqueous solutions. More details can be found in the Full Paper on page 1468 (DOI: 10.1002/cssc.201400028). [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • This strategy offers a new approach for the radical dithiolation of alkynes. • Extremely low catalyst loading of both catalysts was required. • Au catalyst helped to initiate the reaction and deliver better stereoselectivity. • Features of this reaction include excellent stereoselectivity and atom economy. Abstract We report a gold and photoredox combined radical approach for the rapid synthesis of thio-functionalized vinylsulfones from alkynes. Key features of this method include very mild conditions, broad substrate scope, excellent regio- and stereoselectivties, and 100% atom economy. [ABSTRACT FROM AUTHOR]

We report the selective formation of endoperoxides by aerobic TiO 2 photocatalysis through the cyclic addition of dioxygen and a non-conjugated diene, the first heterogeneous catalytic system for endoperoxide synthesis. This green protocol does not require any additive and the photocatalyst is abundant and recyclable, providing a yield up to 64% and >20:1 diastereoselectivity. Mechanistic investigations were carried out by using product analysis, kinetic studies, O-18 labelling experiments, electron-spin resonance and a set of quenching experiments. Superoxide (but not singlet oxygen, triplet oxygen or peroxide) is directly involved in the reaction cascade to form the endoperoxide product. The new findings may be helpful for future for designing eco-friendly and energy sustainable strategies for selective oxygenation reactions using semiconductors, O 2 and sunlight. [ABSTRACT FROM AUTHOR]

To improve dispersibility of graphene for photocatalytic hydrogen evolution in water, hydrophilic reduced graphene GJ600 was simply prepared in situ through one-pot ring-opening reaction between graphene oxide precursor and industrial Jeffamine M-600 polyetheramine, which shows good dispersibility in an aqueous solution, and strong affinity toward metal ions. These features have been integrated to construct an enhanced photocatalytic H 2 evolution system, in which eosin Y was employed as the photosensitizer, triethanolamine (TEOA) as the sacrificial electron donor, low cost Co 2+ as the catalytic precursor. During irradiation by visible light, the aggregation of catalytic centre and graphene is greatly suppressed, and ∼3.78 times enhancement of photocatalytic H 2 evolution is achieved as compared with the system in the absence of graphene. By using HRTEM, XRD, XPS, ICP-AES, as well as spectroscopic and electrochemical approaches, an in situ formed core@shell composites of Co x /Co(TEOA) y (GJ600) z on the basal plane of the graphene sheets is verified as the real catalytic structure. This polymer-modified graphene not only help with the multi-electron transfer between photosensitizer and the catalytic metal centre but also facilitate the formation of this unique core@shell nanocomposites for efficient photocatalytic H 2 evolution. [ABSTRACT FROM AUTHOR]

Hydrophobic quaternary AgInZn 7 S 9 nanorods with good visible-light response prepared via high-temperature pyrolysis method were transferred into aqueous solutions by inserting surfactants into their hydrophobic ligand layer for improved photocatalytic H 2 production. Photocatalytic H 2 evolution tests of AgInZn 7 S 9 nanorods showed that the surfactants on their surfaces have a significant effect on their H 2 evolution activities. Specifically, anionic surfactants can promote H 2 evolution by enriching protons on the surface of AgInZn 7 S 9 nanorods. [ABSTRACT FROM AUTHOR]

A novel K2Nb2O6 photocatalyst with pyrochlore structure has been synthesized via a facile one-pot hydrothermal route with no aid of additives. The as-prepared samples were characterized by powder X-ray diffraction, ultraviolet-visible spectroscopy and field emission scanning electron microscopy. The photocatalytic H2 evolution was performed in an aqueous methanol solution under UV light irradiation. The as-prepared K2Nb2O6 photocatalyst with pyrochlore structure showed higher H2 production activity than that of perovskite KNbO3 and commercial Nb2O5 powders in the absence of cocatalysts, due mainly to its unique crystal and energy band structures. The rate of H2 evolution can be significantly enhanced by loading of Pt nanoparticles. The highest H2 evolution rate of 121 µmol/h was reached when 0.7 wt% Pt nanoparticles were used, which was about 20 times higher than that of pristine K2Nb2O6. [ABSTRACT FROM AUTHOR]

Highlights: [•] Au/m-Ta2O5 photocatalyst was first prepared via a facile photodeposition method. [•] Catalyst exhibited enhanced visible light activities in water splitting for H2. [•] Catalyst exhibited enhanced visible light activities in photodegradation of RhB. [•] SPR effect of Au plays a critical role for the enhanced visible light activities. [•] Large surface area and mesoporous structure is also related to enhanced activities. [ABSTRACT FROM AUTHOR]

• A Ti-based molecular photocatalyst is used in visible-light photocatalysis. • A green and cost-effective approach for transformation of toluene and benzyl alcohol to benzaldehyde is developed. • Br–-doping extends the absorption edge of the Ti-oxide cluster to the visible light region. Photocatalytic selective oxidation using sunlight and O 2 can serve as a green and cost-effective method for the transformation of organic raw materials to value-added products. Here, we report a [Ti 6 O 8 (OH 2) 20 ]8+ cluster modified with Br– (denoted as Ti 6 B) triggers the selective conversion of toluene and benzyl alcohol to benzaldehyde under visible light irradiation with high efficiency. The absorption edge of Ti 6 B in MeCN solution is ca. 500 nm. The conversion of toluene, operated under non-solvent conditions, reached 4.7% with ca. 80% selectivity. The yield of benzaldehyde from benzyl alcohol reached 96%. Common substituents could be tolerated. ESR analyses indicate superoxide is directly involved in the reactions. The results of 17O NMR, IR and small angle scattering indicate Ti 6 B is the true photocatalyst. Mechanistic studies suggest Br– binds to Ti4+ at the Ti-oxo core of Ti 6 B and the photo-driven electronic transition is from HOMO comprised of Br2p to LUMO + 1 comprised of Ti3d orbitals. [ABSTRACT FROM AUTHOR]

The combination of cupric triflate with acridinium photosensitizer MMAP is an efficient catalytic system for the oxidative photocatalytic cross-coupling of isochromans with β-keto esters, 2,4-pentadione, and benzoylnitromethane as nucleophiles. [ABSTRACT FROM AUTHOR]

The new title photocatalyst is hydrothermally synthesized from a mixture of Nb2O5 and KOH in H2O (autoclave, 240 °C, 12 h). [ABSTRACT FROM AUTHOR]

The photocatalytic reduction of nitroarenes (I) with triethanolamine proceeds chemoselectively to afford anilines (II), whilst the reaction of 2-cyanonitrobenzene (III) affords 2-aminobenzamide (IV). [ABSTRACT FROM AUTHOR]