Facile preparation of Chevreul's salt (Cu2SO3·CuSO3·2H2O) mesocrystalline microspheres and their high photocatalytic activity

Cu₂SO₃·CuSO₃·2H₂O mesocrystalline microspheres with excellent photocatalytic performance, composed of sub-microparticles in an oriented fashion, are synthesized by a facile method.

Efficient photocatalytic selective nitro-reduction and C–H bond oxidation over ultrathin sheet mediated CdS flowers

Visible light driven selective nitro reduction and oxidation of saturated sp³ C–H bonds using ultrathin (0.8 nm) sheet mediated uniform CdS flowers as catalyst under a household 40 W CFL lamp using molecular oxygen as oxidant is reported.

Carbon coating stabilized Ti3+-doped TiO2 for photocatalytic hydrogen generation under visible light irradiation

A carbon coating method to stabilize the Ti³⁺-doped TiO₂ photocatalyst for stable and efficient hydrogen production under visible light irradiation is proposed.

One-step hydrothermal synthesis of flowerlike MoS2/CdS heterostructures for enhanced visible-light photocatalytic activities

Flowerlike MoS₂/CdS heterostructures are prepared by a simple hydrothermal method and they show higher photocatalytic activity under the excitation of visible light.

Hollow nanospheres constructed by CoS2 nanosheets with a nitrogen-doped-carbon coating for energy-storage and photocatalysis

Hierarchical CoS2 hollow nanospheres (HSs) with a nitrogen-doped-carbon coating (NC@CoS2 ) are fabricated by a simple solution method. The uniform 300 nm-sized NC@CoS2 HSs are composed of ultrathin nanosheet subunits with a thickness of around 2 nm. It was found that polyvinylpyrrolidone and ethylenediamine not only controlled the morphology of the products, but also provided the sources of nitrogen-doped carbon. Benefiting from their unique structural characteristics, hierarchical NC@CoS2 HSs can be applied in lithium-ion batteries, supercapacitors, and photocatalysis. When evaluated as an electrode material, NC@CoS2 with a coating of optimal thickness showed a high lithium-storage capability with a good cycling stability. Moreover, NC@CoS2 had a remarkable supercapacitive performance and photocatalytic activity. The attractive electrochemical and photocatalytic performances were attributed to the overall structural features of the NC@CoS2 hollow spheres: the N-doped-carbon (NC) coating, hollow interior, and ultrathin nanosheets.

Hydrothermal preparation of hybrid carbon/silica monolithic capillary column for liquid chromatography

A simple, easy and economical approach for the preparation of a hybrid carbon/silica monolithic capillary column was described for the first time by using silica monolith as framework in combination with hydrothermal carbonization at 180°C. During the preparation process, formamide was introduced to the reaction solutions to reduce the dissolution rate of monolithic silica skeleton and its optimal concentration was 1.5 M. Fourier transform infrared spectrometry, scanning electron microscopy, energy dispersive X-ray spectrometry, and inverse size exclusion chromatography were carried out to characterize the as-prepared column. The results demonstrated that carbon spheres ranging from 150 to 1000 nm were successfully attached to the surface of silica skeleton. The prepared hybrid carbon/silica column had a permeability of 4.4 × 10(-14) m(2). Chromatographic performance of the column was evaluated by separation of various compounds including alkylbenzenes, nucleosides and bases, and aromatic acids. The column exhibited an efficiency of 75,000 plates/m for butylbenzene at the optimal linear velocity of 0.23 mm/s. The successful separation of these compounds and the study on mechanism indicated that the column can be applied in mixed-mode chromatography.

Furfural-induced hydrothermal synthesis of ZnO@C gemel hexagonal microrods with enhanced photocatalytic activity and stability

Here we report the synthesis of ZnO@C coaxial gemel hexagonal microrods with a thin hydrothermal carbon (HTC) layer on their surface by a facile one-step hydrothermal method with furfural as the carbon precursor. The furfural has a unique dual role, which not only induces the nucleation of ZnO in the initial stage of hydrothermal process, but also forms a thin HTC layer deposited on the ZnO surface. The thickness of the surface HTC layer increases with the hydrothermal time until 16 h under the conditions adopted in the present study. It has been found that the HTC layer has resulted in a significant improvement in the photocatalytic activities and photostabilities of the ZnO@C microrods for the UV-irradiated photodegradation of methylene blue solution. The mechanism involved in the process is proposed and discussed in terms of the photodegradation scheme and the properties of the ZnO@C microrods.

Selective photoredox using graphene-based composite photocatalysts

Graphene (GR) has proven to be a promising candidate to construct effective GR-based composite photocatalysts with enhanced catalytic activities for solar energy conversion. During the past few years, various GR-based composite photocatalysts have been developed and applied in a myriad of fields. In this perspective review, compared with the traditional applications of GR-based nanocomposites for the "non-selective" degradation of pollutants, photo-deactivation of bacteria and water splitting to H2 and O2, we mainly focus on the recent progress in the applications of GR-based composite photocatalysts for "selective" organic transformations, including reduction of CO2 to renewable fuels, reduction of nitroaromatic compounds to amino compounds, oxidation of alcohols to aldehydes and acids, epoxidation of alkenes, hydroxylation of phenol, and oxidation of tertiary amines. The different roles of GR in these GR-based nanocomposite photocatalysts such as providing a photoelectron reservoir and performing as an organic dye-like macromolecular photosensitizer have been summarized. In addition, graphene oxide (GO) as a co-catalyst in GO-organic species photocatalysts and GO itself as a photocatalyst for selective reduction of CO2 have also been demonstrated. Finally, perspectives on the future research direction of GR-based composite photocatalysts toward selective organic redox transformations are discussed and it is clear that there is a wide scope of opportunities awaiting us in this promising research field.

Synthesis of ultrathin CdS nanosheets as efficient visible-light-driven water splitting photocatalysts for hydrogen evolution

Ultrathin CdS nanosheets with a thickness of ~4 nm have been synthesized through an ultrasonic-induced aqueous exfoliation method involving lamellar CdS-DETA hybrid nanosheets as starting materials and L-cysteine as a stabilizing agent. The as-obtained CdS ultrathin nanosheets exhibit efficient photocatalytic activity and good stability for hydrogen production.

Carbon nanocoating: an effective nanoreactor towards well-defined carbon-coated GaN hollow nanospindles

Carbon-coated GaN hollow nanospindles with uniform morphology and good structural stability are facilely prepared by nitridizing solid carbon-coated GaOOH nanospindles in an ammonia atmosphere at 800 °C for 2 h. The carbon nanocoating acts as a nanoreactor which not only preserves the spindle-like morphology, but also prevents the growth of GaN particles during the thermal treatment. The significant advantage is that the hollow nanostructures so obtained exhibit superior resistance to distortion, collapse, and shrinkage.

Constructing atomic layer g-C3N4–CdS nanoheterojunctions with efficiently enhanced visible light photocatalytic activity

CdS nanoparticles were grown in situ on atomic layer g-C₃N₄ to form nanoheterojunctions. The synergic effect between CdS and atomic layer g-C₃N₄ plays a pivotal role for improving the photoactivity.

Facile non-hydrothermal synthesis of oligosaccharides coated sub-5 nm magnetic iron oxide nanoparticles with dual MRI contrast enhancement effect

Ultrafine sub-5 nm magnetic iron oxide nanoparticles coated with oligosaccharides (SIO) with dual T1-T2 weighted contrast enhancing effect and fast clearance has been developed as magnetic resonance imaging (MRI) contrast agent. Excellent water solubility, biocompatibility and high stability of such sub-5 nm SIO nanoparticles were achieved by using the "in-situ polymerization" coating method, which enables glucose forming oligosaccharides directly on the surface of hydrophobic iron oxide nanocrystals. Reported ultrafine SIO nanoparticles exhibit a longitudinal relaxivity (r1) of 4.1 mM-1s-1 and a r1/r2 ratio of 0.25 at 3 T (clinical field strength), rendering improved T1 or "brighter" contrast enhancement in T1-weighted MRI in addition to typical T2 or "darkening" contrast of conventional iron oxide nanoparticles. Such dual contrast effect can be demonstrated in liver imaging with T2 "darkening" contrast in the liver parenchyma but T1 "bright" contrast in the hepatic vasculature. More importantly, this new class of ultrafine sub-5 nm iron oxide nanoparticles showed much faster body clearance than those with larger sizes, promising better safety for clinical applications.

Enhanced extrinsic absorption promotes the visible light photocatalytic activity of wide band-gap (BiO)2CO3 hierarchical structure

(BiO)₂CO₃ hierarchical microspheres showed higher visible light photocatalytic activity due to enhanced extrinsic absorption benefiting from light reflecting and scattering.

Perfect inhibition of CdS photocorrosion by graphene sheltering engineering on TiO2 nanotube array for highly stable photocatalytic activity

An artful graphene-sheltering engineering has been developed for perfect inhibition of CdS photocorrosion.

Efficient visible-light photocatalytic hydrogen evolution and enhanced photostability of core/shell CdS/g-C3N4 nanowires

CdS/g-C3N4 core/shell nanowires with different g-C3N4 contents were fabricated by a combined solvothermal and chemisorption method and characterized by X-ray powder diffraction, scanning electronic microscopy, transmission electron microscopy, and UV-vis diffuse reflection spectroscopy. The photocatalytic hydrogen-production activities of these samples were evaluated using Na2S and Na2SO3 as sacrificial reagents in water under visible-light illumination (λ≥420 nm). The results show that after a spontaneous adsorption process g-C3N4 is successfully coated on CdS nanowires with intimate contact and can significantly improve the photocatalytic hydrogen-production rate of CdS nanowires, which reaches an optimal value of up to 4152 μmol h(-1) g(-1) at the g-C3N4 content of 2 wt %. More importantly, g-C3N4 coating can substantially reinforce the photostability of CdS nanowires even in a nonsacrificial system. The synergic effect between g-C3N4 and CdS, which can effectively accelerate the charge separation and transfer corrosive holes from CdS to robust C3N4, was proposed to be responsible for the enhancement of the photocatalytic activity and photostability. The possible conditions necessary for the synergic effect to work in a CdS/g-C3N4 core/shell configuration is also discussed.