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The localized surface plasmon resonance (LSPR) of noble metals has been investigated for decades for applications in various catalysis reactions and optical research studies, but its development has been hampered by inefficient light absorption and high costs. In comparison, the creation of less expensive semiconductors (metal oxides) with strong plasmonic absorption is an appealing option, particularly defective molybdenum oxide (HxMoO3−y) has received considerable attention and investigation as a promising plasmonic material for a variety of catalytic reactions (photocatalysis, thermocatalysis, photothermal catalysis, etc.).The LSPR effect of HxMoO3−y can be tuned throughout a broad spectrum range from visible to near-infrared (NIR) by altering the doping amount by electrochemical control, chemical reduction, or photochemical control. Notably, defects (oxygen vacancies) in HxMoO3−y arise in conjunction with the LSPR effect, resulting in the formation of unique and useful active sites in a range of catalytic processes. In this review, we explore the formation mechanism of HxMoO3−y with plasmonic features and discuss its applications in photocatalysis, thermocatalysis, and photothermal catalysis. [ABSTRACT FROM AUTHOR]

p‐Nitrophenol (PNP) has aroused much concern due to its high toxicity in industrial wastewater and drinking water. Herein, we designed a new plasmonic RuPd/HxMoO3–y catalyst synthesized by a simple impregnation method, followed by H2 atmosphere reduction. The synthesized RuPd/HxMoO3–y hybrid, having RuPd alloy nanoparticles (NPs) anchored on HxMoO3–y, namely hydrogen‐doped molybdenum oxide support, shows a strong localized surface plasmon resonance (LSPR) absorption peak at around 639 nm. Photocatalytic activity of Ru/HxMoO3–y hybrid for the reduction of PNP to p‐aminophenol (PAP) under visible light irradiation can be dramatically improved by alloying with Pd atoms. More importantly, a reasonable mechanism for PNP reduction is proposed. We find that synergetic effect between HxMoO3–y and RuPd alloy NPs of RuPd/HxMoO3–y plays a vital role in photocatalytic reduction, in which RuPd alloy NPs act as the active species and plasmonic HxMoO3–y acts as electron‐donation centre. [ABSTRACT FROM AUTHOR]

Much effort has been devoted to photocatalytic production of hydrogen peroxide (H2O2) as an alternative to fossil fuels. From an economic point of view, reductive synthesis of H2O2 from O2 coupled with the oxidative synthesis of value‐added products is particularly interesting. We herein report application of MIL‐125‐NH2, a photoactive metal–organic framework (MOF), to a benzylalcohol/water two‐phase system that realized photocatalytic production and spontaneous separation of H2O2 and benzaldehyde. Hydrophobization of the MOF enabled its separation from the aqueous phase. This resulted in enhanced photocatalytic efficiency and enabled application of various aqueous solutions including extremely low pH solution which is favorable for H2O2 production but fatal to MOF structure. In addition, a highly concentrated H2O2 solution was obtained by simply reducing the volume of the aqueous phase. In the right phase: Hydrogen peroxide (H2O2) is produced in a two‐phase water/benzylalcohol system which contains MIL‐125‐NH2, a Ti‐containing metal–organic framework (MOF) as the photocatalyst. Two products of the catalysis, H2O2 and benzaldehyde, spontaneously separated into the two phases. Hydrophobized MOF dispersed to the organic phase, which enhanced activity and also made it possible to apply various harsh aqueous phases in the photocatalysis. [ABSTRACT FROM AUTHOR]

Molybdenum disulfide (MoS2) has been regarded as a favorable photocatalytic co‐catalyst and efficient hydrogen evolution reaction (HER) electrocatalyst alternative to expensive noble‐metals catalysts, owing to earth‐abundance, proper band gap, high surface area, and fast electron transfer ability. In order to achieve a higher catalytic efficiency, defects strategies such as phase engineering and vacancy introduction are considered as promising methods for natural 2H‐MoS2 to increase its active sites and promote electron transfer rate. In this study, we report a new two‐step defect engineering process to generate vacancies‐rich hybrid‐phase MoS2 and to introduce Ru particles at the same time, which includes hydrothermal reaction and a subsequent hydrogen reduction. Compositional and structural properties of the synthesized defects‐rich MoS2 are investigated by XRD, XPS, XAFS and Raman measurements, and the electrochemical hydrogen evolution reaction performance, as well as photocatalytic hydrogen evolution performance in the ammonia borane dehydrogenation are evaluated. Both catalytic activities are boosted with the increase of defects concentrations in MoS2, which ascertains that the defects engineering is a promising route to promote catalytic performance of MoS2. Having major defects: Defect engineering of MoS2 to improve electrocatalytic/photocatalytic performances for hydrogen production was examined. [ABSTRACT FROM AUTHOR]

Abstract: Although black phosphorus (BP) is an interesting 2D nanosheet material with a high hole mobility, its application in the photocatalytic water oxidation for O2 evolution is not reported yet. Herein the use of BP coupled with a reductive hydroxide, Ni(OH)2, is reported for the first time. The developed photo‐assisted process confirms that the BP XPS measurements confirm that the oxidation state of BP is reduced through the photo‐assisted loading method. The obtained P−Ni(OH)2 samples present the steady and efficient photocatalytic water splitting for O2 generation. Under the simulated sunlight irradiation in 0.1 M Na2S2O4 solution, the O2 generation rate can reach up to 15.7 μmol/(gcatalyst*h) or 224.3 μmol/(gBP*h). The density functional theory (DFT) calculation suggests that the electrons and holes move to surface of BP and Ni(OH)2, respectively. The merit of self‐polarization of P−Ni(OH)2 ensures the stability of BP and achieves the photocatalytic O2 generation from water. [ABSTRACT FROM AUTHOR]

Abstract: Single‐site photocatalysts generally display excellent photocatalytic activity and considerably high stability compared with homogeneous catalytic systems. A rational structural design of single‐site photocatalysts with isolated, uniform, and spatially separated active sites in a given solid is of prime importance to achieve high photocatalytic activity. Intense attention has been focused on the design and fabrication of single‐site photocatalysts by using porous materials as a platform. Metal–organic frameworks (MOFs) have great potential in the design and fabrication of single‐site photocatalysts due to their remarkable porosity, ultrahigh surface area, extraordinary tailorability, and significant diversity. MOFs can provide an abundant number of binding sites to anchor active sites, which results in a significant enhancement in photocatalytic performance. In this focus review, the development of single‐site MOF photocatalysts that perform important and challenging chemical redox reactions, such as photocatalytic H2 production, photocatalytic CO2 conversion, and organic transformations, is summarized thoroughly. Successful strategies for the construction of single‐site MOF photocatalysts are summarized and major challenges in their practical applications are noted. [ABSTRACT FROM AUTHOR]

In this work, a composite photocatalyst of TiO 2 supported on the slag-made calcium silicate (TiO 2 /SCS) was synthesized by employing a facile mixing process and using blast furnace slag as a low-cost and abundant precursor of SCS. The characterization results revealed that the open framework structure of SCS was covered by well-dispersed TiO 2 nanoparticle aggregates, indicating the close combination of titania and calcium silicate in the TiO 2 /SCS photocatalyst. Higher specific surface areas could be obtained for TiO 2 /PCS (PCS: pure calcium silicate) and TiO 2 /SCS composites, indicating their better adsorption capabilities than that of bare TiO 2 . The degradation of methylene blue (MB) by TiO 2 , TiO 2 /PCS and TiO 2 /SCS composites with different weight percentages of titania was carried out under UV-light irradiation to systematically investigate their photocatalytic activities, and the TiO 2 content of 60 wt% (TiO 2 -60/SCS) was found to be the best one to achieve the maximum rate of MB degradation, which may be due to the high specific surface area and good adsorption capacity of the composite photocatalysts. The degradation of methyl violet (MV) and methyl orange (MO) dyes indicated that the obtained photocatalysts can effectively adsorb cationic molecules (MB and MV) but have little absorption toward negatively charged molecules (MO), which play a key role in the subsequent photocatalytic degradation of dye pollutants. [ABSTRACT FROM AUTHOR]

A novel and facile method to fabricate yolk-shell nanostructured photocatalysts consisting of TiO2 nanoparticles (NPs) as the core and spherical hollow silica as the shell was developed. In the fabrication, commercial TiO2 NPs were directly incorporated into hollow silica spheres by utilizing oil-in-water (O/W) microemulsions as a template, followed by heat treatment to create a void space between the TiO2 core and the silica shell region. The synthesized yolk-shell nanostructured TiO2@SiO2 acts as an efficient photocatalyst with both improved adsorption properties and photocatalytic efficiency, which far outperformed those of naked TiO2 owing to the ability of the porous silica shell to adsorb/enrich small organic reactants (acetaldehyde and 2-propanol) inside the void space and efficient transportation to the adjacent active TiO2 core. Comparative photocatalytic tests using a large organic molecule (conalbumin) revealed that the porous silica shell with an average pore diameter of 2.0 nm endowed this material with a molecular-sieving property, demonstrating its potential application in combination with organic support materials. [ABSTRACT FROM AUTHOR]

The intercalation of CO2 reduction catalyst [Re(bpy)(CO)3Cl] (bpy=2,2′-bipyridine) into a layered zirconium phosphate (Zr(HPO4)2 ⋅H2O, α-ZrP) with an interlayer distance of 10.3 Å was performed. XRD, IR spectroscopy, and extended X-ray absorption fine structure measurements provided strong evidence that the Re complexes were intercalated into the layered interspace without significant structural change. The visible-light photoredox system for the catalytic conversion of CO2 was constructed by using Re/ZrP as catalyst, Rhodamine B as photosensitizer, and triethanolamine as a sacrificial reagent. The emission intensity of Rhodamine B near λ=580 nm decreased with increasing amount of intercalated Re complex, suggesting the occurrence of an electron transfer from Rhodamine B to the Re complex. Performing the reaction with isotopic 13CO2 demonstrated that the CO produced originated mostly from CO2. Furthermore, this CO2 reduction system showed remarkable durability and could be used repeatedly without significant loss in activity. [ABSTRACT FROM AUTHOR]

Abstract: Preparation of highly hydrophobic FAU zeolite has been achieved by a two-step preparation method that comprises predealumination treatment using concentrated mineral acids and subsequent calcination treatment. The hydrophilic/hydrophobic character of the zeolites was estimated by detailed adsorption measurements using water and toluene molecules as adsorbates, which showed the strict hydrophobic nature of the prepared FAU zeolites. By means of TG, FT-IR, and 29Si MAS NMR analyses, it was concluded that the enhancement in hydrophobicity originates from the healing of silanol defect sites and the formation of a refined silica surface with fewer adsorption sites. Thus-prepared FAU zeolite, with high crystallinity, structural and thermal stability, and hydrophobicity, significantly improved the photocatalytic degradation rates of 2-propanol in water and acetaldehyde in air on TiO2 when it was used as a catalyst support. A distinct correlation was found between the hydrophobicity of zeolites and photocatalytic activity of the supported TiO2. [Copyright &y& Elsevier]

Through the simple process using alkoxide reagent containing fluorine, triethoxyfluorosilane (TEFS), hydrophobic mesoporous silica material (HMS) was prepared. The surface modified HMS have still maintained its mesoporous structure and large surface area and showed considerable hydrophobic property compared with non-modified HMS. Moreover the surface modified HMS was applied as a support of TiO2 photocatalyst with the aim of the efficient degradation of organic pollutant in water. Due to the hydrophobic property, the fine TiO2 photocatalyst particles were generated on the modified HMS and both the adsorption properties and photocatalytic activities for the degradation of 2-propanol diluted in water were dramatically increased. [ABSTRACT FROM AUTHOR]

Steel slag, commercial waste material containing silica and alumina which are the chemical components elements of zeolite, was used as a source for synthesis of FAU zeolite (Y-zeolite, X-zeolite). Through acid-treatment to remove CaO species from steel slag and hydrothermal treatment, well-crystallized Na type FAU zeolite was obtained. Furthermore the synthesized FAU zeolite was applied as a support of photocatalyst. It was found that hydrophobic surface property of zeolite enhances photocatalytic activity for decomposition of organic pollutants and the zeolite synthesized from steel slag would be applicable as promising support of TiO2 photocatalyst. [ABSTRACT FROM AUTHOR]

Hydrogen peroxide (H 2 O 2) has attracted considerable interest due to its status as an eco-friendly oxidant and a sustainable energy carrier. This review summarizes current advancements in various photocatalysts, including metal-organic frameworks (MOFs), covalent-organic frameworks (COFs), titanium dioxide (TiO 2), ionic carbon nitride, quantum dots (QDs), coordination polymer (CP), and heterojunction materials, applied for H 2 O 2 production in several types of two-phase systems, composed of benzyl alcohol (BA), toluene or octanol organic phase and water phase. Such two-phase media enables spontaneous separation of the produced reduction product (H 2 O 2) from oxidation product, benzaldehyde (BAL) or octanal and photocatalysts suppressing H 2 O 2 decomposition. The goal of the present review is to provide more fresh perspective on the future developments in the field of sustainable H 2 O 2 production in two-phase system. [Display omitted] • Two-phase systems with organic and water phases were used in H 2 O 2 photo-synthesis. • The biphasic system inhibits H 2 O 2 decomposition via separating H 2 O 2 from catalysts. • Different methods of hydrophobic modification on diverse materials were summarized. • Autocatalysis of benzyl alcohol/benzaldehyde shows little impact on this system. [ABSTRACT FROM AUTHOR]

Employing photocatalytic technology for efficient water splitting to hydrogen evolution is a sustainable and renewable solution for energy and environmental issues. Large‐scale utilization of solar hydrogen requires the appropriate usage of photocatalysts with high efficiency and their easy integration into solar devices. Recently, 2D materials have been widely studied because of their potential utility in device fabrication. Black phosphorus (BP) is a newly developed 2D direct bandgap semiconductor with an impressive tunable bandgap and fast carrier migration characteristics. In this review, the optical and electronic characteristics of 2D phosphorene‐based materials are mainly discussed in terms of water splitting reaction. Density functional theory calculations are first summarized, followed by brief discussions on the direct application of BP in photocatalytic water splitting based on recent reports. This review might assist researchers to design new materials for photocatalytic water splitting. Black phosphorus (BP) is an interesting and promising 2D candidate for energy conversion and storage. This review focuses on photocatalytic water splitting of BP‐based samples from the view of theoretical calculation and experimental aspects. This review could help researchers design new materials for photocatalytic water splitting. [ABSTRACT FROM AUTHOR]

Photocatalytic synthesis of hydrogen peroxide (H 2 O 2) coupled with benzyl alcohol (BA) oxidation reaction is preferred based on the economic consideration. Herein, we developed a hydrophobic TiO 2 material (DNOPA-TiO 2), co-modified with 2,3-dihydroxynaphthalene (2,3-DN) and octadecylphosphonic acid (OPA), which enables H 2 O 2 synthesis under visible-light-irradiation in a two-phase system consisting of BA and water. This system allows the separation of generated H 2 O 2 in the aqueous phase from benzaldehyde (BAL), the product of BA oxidation, present in the organic phase. The hydrophobic DN2OPA2-TiO 2 exhibited higher and more stable H 2 O 2 production (3522 μmol L−1) over an 8-hour reaction under visible light (λ > 450 nm). The addition of 2,3-DN facilitates visible light harvesting and donates electrons to TiO 2 through the formation of charge-transfer complexes, which promotes the O 2 reduction reaction (ORR) and improves H 2 O 2 production. Moreover, the remarkable stability of DN2OPA2-TiO 2 is originated from the hydrophobic nature of the catalysts thanks to OPA modification. This modification allows TiO 2 to exist in the organic phase with better dispersion, inhibiting the decomposition of H 2 O 2 resulting from direct contact between produced H 2 O 2 and TiO 2. [Display omitted] • DN/OPA-TiO 2 is used for photocatalytic H 2 O 2 production in a two-phase system. • 2,3-DN enhances visible light absorption by forming charge-transfer complexes. • OPA imparts TiO 2 hydrophobic and inhibits the decomposition of produced H 2 O 2. • DN2OPA2-TiO 2 exhibits higher visible-light activity (3522 μmol L−1, λ > 450 nm). [ABSTRACT FROM AUTHOR]

The inside back cover of the journal "Chemistry: A European Journal" is presented.

The Front Cover image shows various photocatalysts such as nano‐sized TiO2, transition‐metal‐oxide moieties (single‐site photocatalysts), plasmonic metal nanostructures, and metal complexes displaying various light‐excited photocatalytic processes. All of the processes occur in the nanospace of mesoporous silica‐based materials, which possess high surface areas, transparency to UV and visible light as well as easily modified surfaces. More details can be found in the Minireview by Yamashita et al. on page 1528 (DOI: 10.1002/cssc.201400111), while more information about the research group is available in the Cover Profile (DOI: 10.1002/cssc.201400098). [ABSTRACT FROM AUTHOR]

The Front Cover artwork is provided by the group of Prof. Hiromi Yamashita from Osaka University. The image shows four photocatalytic systems assembled on transparent mesoporous silica materials with the background of environmental remedy and solar energy utilization. The Minireview itself is available at [ABSTRACT FROM AUTHOR]

Photoinduced reactive oxygen species (ROSs)-involving nitrogen oxide (NO x) abatement offers a green way to mitigate environmental air pollution. Developing cost-effective photocatalysts remains challenging yet crucial. Herein, an atomically dispersed Mg-modified g-C 3 N 4 nanosheet photocatalyst (x Mg-CN) with excellent photoactivity is developed. The 1.0Mg-CN sample delivers a high NO removal rate of 52.3% under visible light irradiation within 30 min, far surpassing the Mg-free analog (CN, 41.2%). Moreover, a suppressed NO 2 by-product discharge can be achieved. The introduction of Mg single atoms (SAs) alters the charge density distribution on the triazine ring plane of g-C 3 N 4 , inducing the formation of a built-in electric field, which improves the photoexcited charge carrier separation. Additionally, Mg SAs contribute to the adsorption and activation of O 2 molecules, resulting in enhanced ROSs production, as evidenced by the experiments and theoretical simulations. The findings shed light on the role of SAs in designing highly efficient g-C 3 N 4 -based photocatalysts for air purification. [Display omitted] • Roles of Mg single atoms in enhancing the NO photo-oxidation ability of g-C3N4 are revealed for the first time. • A facile synthesis strategy for single-atom-based g-C3N4 catalysts is reported. • A locally built-in electric field is formed after introducing Mg single atom. • Enhanced oxygen adsorption/activation and ROS generation are studied. [ABSTRACT FROM AUTHOR]

Recently, the combination of photocatalytic reduction and oxidation reactions has attracted great attention, especially for the photocatalytic synthesis of hydrogen peroxide (H 2 O 2) integrated with benzyl alcohol (BA) oxidation reaction. The plasmonic Au nanoparticles (NPs) driven by surface plasmon resonance (SPR) excitation can be efficiently applied for photocatalysis. In this study, the effect of a hydrophobic Au-deposited TiO 2 material (OPA-Au/TiO 2) modified with octadecylphosphonic acid (OPA) on the photosynthesis H 2 O 2 performance in a two-phase system, comprising water and BA phases, is investigated. The SPR effect of plasmonic Au NPs facilitates the generation of substantial photoexcited hot electrons, which transfer to the conductive band of TiO 2. Moreover, OPA-Au/TiO 2 present in the BA phase, exhibits dramatically enhanced activity (567 μmol g−1 h−1) under λ > 420 nm irradiation owing to the separation from produced H 2 O 2 in the aqueous phase, which efficiently suppresses the H 2 O 2 decomposition. [Display omitted] • OPA-modified Au/TiO 2 is effective for biphasic photocatalytic H 2 O 2 production. • Au with surface plasmon resonance provides rich hot electrons for TiO 2. • OPA imparts TiO 2 hydrophobic and inhibits the decomposition of produced H 2 O 2. • OPA-Au/TiO 2 exhibits enhanced visible-light activity (567 μmol g−1 L−1, λ > 420 nm). [ABSTRACT FROM AUTHOR]

Review: 96 refs. [ABSTRACT FROM AUTHOR]