Correction for ‘Carbon quantum dots as a visible light sensitizer to significantly increase the solar water splitting performance of bismuth vanadate photoanodes’ by Kai-Hang Ye et al., Energy Environ. Sci., 2017, DOI: 10.1039/c6ee03442j.

Here, we demonstrate that carbon quantum dots (CQDs), as a low cost, chemically stable, and environmentally friendly photosensitizer, can dramatically broaden the light absorption range to the entire visible range. Consequently, the NiOOH/FeOOH/CQD/BiVO4 (NFCB) photoanode has achieved a remarkable photocurrent density of 5.99 mA cm−2 at 1.23 V vs. RHE under AM 1.5G in KH2PO4 aqueous solution without a hole scavenger (pH = 7) and a record high applied bias photon-to-current efficiency of 2.29% at 0.6 V vs. RHE for BiVO4-based photoanodes. This novel NFCB photoanode could operate stably for 10 h with a Faraday efficiency of ∼95%, demonstrating the great potential of using CQDs for solar water splitting.

•3D-3D porous Bi2WO6/graphene hydrogel (BWO/GH) composite was synthesized by a facile one-step hydrothermal method.•It achieves the homogeneous dispersion of the 3D flower-like BWO in GH by controlling the growth of BWO precursors.•3D-structured BWO/GH composite realized the synergistic effect of adsorption and photocatalysis.•The 3D multilevel structure of BWO/GH composite highly improves the utilization rate of light.•It shows new insights for the development of BWO/GH photocatalyst and application of water purification in dynamic system.A novel visible-light 3D-3D Bi2WO6/graphene hydrogel (BWO/GH) photocatalyst with the synergistic effect of adsorption and photocatalysis has been successfully synthesized by a facile one-step hydrothermal method and is applied in environment remediation. 3D porous graphene hydrogel, in which 3D-structured flower-like BWO as an efficient photocatalyst is homogenously distributed, not only exhibits the great absorption toward the organic pollution, but also provides multidimensional quality and electron transfer channels. The 3D-3D structure of BWO/GH composite is beneficial to light refraction and reflection, which highly improves the utilization rate of light. The synergistic effect of the 3D-3D BWO/GH composite greatly enhanced the removal rates of organic pollutants and it is ease of separation and recycling in water purification. The removal rate of methylene blue (MB) by BWO/GH composite is about 2.3 times as that of the pure BWO in static systems, and the removal rates of MB and 2, 4-dichlorophenol (2, 4-CDP) are about 1.3 and 3 times as these of the pure BWO in dynamic system. When the irradiation time lasted for 74 h, the removal rate of MB is nearly unchanged and still kept at 36.1%, indicating that the 3D BWO/GH composite has a high stability. The construction of BWO/GH composite resolved the adsorption saturation problem of GH and improved the photocatalytic activity of BWO, thus greatly improved the removal rate of water pollutants.Download high-res image (280KB)Download full-size image

•Immobilized BiOCl nanosheets/TiO2 arrays hybrid photocatalyst were fabricated.•The degradation efficiency of BCTO-3 can still reach 91.7% after eight cycles.•The immobilized BCTO-3 can be recycled for removal of organic pollutants in water.Forming a hybrid structure is considered as an efficient strategy toward improving the photocatalytic activity of TiO2-based photocatalyst. In this work, we report a facile impregnation method to prepare BiOCl nanosheets on rutile TiO2 nanorod arrays on transparent conductive fluorine-doped tin oxide (FTO) substrate. According to RhB photocatalytic degradation experiments, the degradation efficiency of the immobilized BiOCl/TiO2 (denoted as BCTO-3) hybrid photocatalyst can reach 99.1% after visible light irradiation for 3 h, and its efficiency is higher than that of pure BiOCl (42.7%) and TiO2 (44.8%), respectively. The enhancement is demonstrated to be the match of energy level between BiOCl and TiO2. Hence, the separation and transfer of photogenerated electron-hole pairs are obviously improved, which have been illustrated by the result of the photoluminescence spectra analysis and photoelectrochemical performance. Moreover, the degradation efficiency of BCTO-3 can still reach 91.7% after eight times photodegradation cycle experiments. Due to the easy recycling and excellent durability, the immobilized BCTO-3 photocatalyst is considered as a promising photocatalytic material for the removal of organic pollutants in aqueous eco-environments.Download high-res image (192KB)Download full-size image

•Cellulose-based non noble metal catalyst for oxygen reduction reaction is studied.•The cellulose-derived carbon is doped with NH3.•Comparable ORR activity with Pt/C catalyst is reached.Nitrogen doped graphitic carbon ribbons are prepared by simultaneously graphitization and nitrogen doping of nano crystalline cellulose at high temperature. Ferrous salt works as catalyst for graphitization, without which amorphous carbon is resulted. The graphitic carbon ribbons and amorphous carbon are compared in detail in morphology, crystalline structure, defects, nitrogen groups and ORR activity by means of SEM, TEM, Raman, XRD, XPS and electrochemical characterizations. It is found the nitrogen doped graphitic carbon ribbons has comparable ORR activity with Pt/C catalyst in alkaline medium, which is much better than nitrogen doped amorphous carbon. The improved ORR activity is ascribed to the nitrogen group introduced by NH3 treatment of graphitic carbon. The as prepared material can work as efficient non noble metal catalyst for the oxygen reduction reaction.

Carboxyl single-walled carbon nanotubes (SWNTs) were used to construct an innovative drug delivery system by modification with chitosan (CHI) to enhance water solubility and biocompatibility. Hyaluronan (HA), as the target ligand for CD44, was bound to the CHI layer to selectively kill cancer cells. To achieve a new treatment strategy for cancer, the drug delivery system was loaded with the anticancer drug doxorubicin hydrochloride (DOX). The data showed that the system loaded with DOX with zeta potentials of 8.52 ± 0.12 mV at pH 7.4 and 12.53 ± 0.23 mV at pH 5.5 had high drug-loading efficiency, reaching 107.73 ± 0.67%. It also exhibited sustained and controlled drug-release, depending on pH; it released less than 10% at pH 7.4 but nearly 85% at pH 5.5 after 72 h. Cell viability results indicated that the drug delivery system effectively killed HeLa cells while it had lower cytotoxicity against fibroblasts. Combined histological examinations and blood property analyses demonstrated that it did not cause severe damage to vital organs in SD rats. Thus, this drug delivery system may provide a high therapeutic efficacy for cancer, while minimising adverse side effects.

A BiOI/SnS2 p–n junction is prepared by depositing BiOI particles on flowerlike SnS2 flakes. The heterojunction formed between p-type BiOI and n-type SnS2 brings greatly improved photocatalytic activity compared with pure SnS2 or BiOI in the degradation of Rhodamine B dye under visible light and sunlight irradiation. The improved photocatalytic performance is explained by the synergetic effects of the formation of a p–n junction between BiOI and SnS2. The migration of photogenerated carriers can be promoted by the electric field established at the heterojunction interfaces, leading to effective separation of the photogenerated electron–hole pairs and reduced electron–hole recombination. The BiOI/SnS2 heterojunction will find promising applications in photocatalysis and solar energy conversion.

Herein, we report a facile approach to synthesize Bi2O3/BiVO4 heterostructures for photoelectrochemical (PEC) cells. Due to the fast separation of the electron–hole pairs as a result of the p–n junction, the Bi2O3/BiVO4 heterostructures achieved a remarkable photocurrent of 2.58 mA cm−2 at 1.2 V vs. Ag/AgCl, which is about 5 times that of the pristine BiVO4.

To overcome the drawback of low photocatalytic efficiency brought by fast electron–hole recombination and narrow photoresponse range, the heterostructured Bi2S3/BiOBr microspheres were designed and synthesized via a facile one-pot solvothermal method. The as-prepared heterostructured Bi2S3/BiOBr photocatalyst exhibits significantly enhanced photoelectrochemical performance and photocatalytic activity for decomposing rhodamine B (RhB) and Brilliant ponceau 5R (BP) compared with pure BiOBr under visible light irradiation, which could be mainly attributed to the formation of a heterojunction in the Bi2S3/BiOBr interface, which can efficiently facilitate the separation of photogenerated electron–hole pairs. Furthermore, a terephthalic acid photoluminescence (TA-PL) probing test and radical trapping experiments demonstrate that the h+ and ·O2− radicals are the dominant reactive species while ·OH radicals could be neglected. In addition, the possible enhanced photocatalytic mechanism is proposed on the basis of the calculated energy band positions and radical trapping experiments.

A novel, mild, inexpensive, nontoxic, and effective, one-pot synthesis of vicinal diamines with benzaldehyde and aniline derivatives mediated by 10% of BiCl3 and 3 equiv of Zn in ethanol at reflux temperature has been developed and systematically investigated. A wide range of substituted vicinal diamines compounds were obtained in good to excellent yields. The scope and limitations of this reaction have been examined. Steric and electronic effects of reactants have been discussed.

•The BiPO4 film was successfully prepared on ITO substrate via dip-coating method.•The PEC degradation rate of methyl blue increased remarkably under photoelectrocatalysis.•The influencing factors of PEC degradation (initial pH value, electrolyte) were investigated.BiPO4 film was fabricated on indium-tin oxide glass substrate via dip-coating method for photoelectrocatalytic (PEC) activity. BiPO4 film has performed a superior PEC degradation ability with synergetic effect of electro-oxidation and photocatalysis. The degradation rate of Methyl Blue (MB) increased greatly as bias potential increased and the highest activity was achieved at the bias potential of 3.0 V (vs. SCE in 0.1 mol/L Na2SO4, pH = 7). The PEC activity of BiPO4 film is 5 times and 15 times higher than that of photocatalytic degradation and electrochemical oxidation, respectively. The acid condition plays an important role in achieving effective photoelectrocatalysis. The PEC degradation rate was also affected by the adsorption and the oxidation reaction of the ions of electrolytes. This BiPO4 film could open up new opportunities to develop high-performance photoanode for PEC degradation.The BiPO4 film loaded on the ITO substrate was used as electrode during the reaction. The applied bias effectively enhanced the separation of photo-induced electron-hole.

•PLGA and PLGA/CNC composite nanofiber membranes were prepared.•Morphology, thermodynamic and mechanical properties of nanofiber membranes were characterized.•Cytocompatibility and cellular responses of nanofiber membranes were studied.•PLGA/CNC composite nanofiber membranes had better cytocompatibility.Although extensively used in the fields of drug-carrier and tissue engineering, the biocompatibility and mechanical properties of polylactide–polyglycolide (PLGA) nanofiber membranes still limit their applications. The objective of this study was to improve their utility by introducing cellulose nanocrystals (CNCs) into PLGA nanofiber membranes. PLGA and PLGA/CNC composite nanofiber membranes were prepared via electrospinning, and the morphology and thermodynamic and mechanical properties of these nanofiber membranes were characterized by scanning electron microscopy (SEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and dynamic mechanical analysis (DMA). The cytocompatibility and cellular responses of the nanofiber membranes were also studied by WST-1 assay, SEM, and confocal laser scanning microscopy (CLSM). Incorporation of CNCs (1, 3, 5, and 7 wt.%) increased the average fiber diameter of the prepared nanofiber membranes from 100 nm (neat PLGA) to ∼400 nm (PLGA/7 wt.% CNC) and improved the thermal stability of the nanofiber membranes. Among the PLGA/CNC composite nanofiber membranes, those loaded with 7 wt.% CNC nanofiber membranes had the best mechanical properties, which were similar to those of human skin. Cell culture results showed that the PLGA/CNC composite nanofiber membranes had better cytocompatibility and facilitated fibroblast adhesion, spreading, and proliferation compared with neat PLGA nanofiber membranes. These preliminary results suggest that PLGA/CNC composite nanofiber membranes are promising new materials for the field of skin tissue engineering.

A novel carbon solid acid catalyst was prepared by incomplete hydrothermal carbonization of β-cyclodextrin into small polycyclic aromatic carbon sheets, followed by the introduction of –SO3H groups via sulfonation with sulfuric acid. The physical and chemical properties of the catalyst were characterized in detail. The catalyst simultaneously catalyzed esterification and transesterification reactions to produce biodiesel from high free fatty acid (FFA) containing oils (55.2 %). For the as-prepared catalyst, 90.82 % of the oleic acid was esterified after 8 h, while the total transesterification yield of high FFA containing oils reached 79.98 % after 12 h. By contrast, the obtained catalyst showed comparable activity to biomass (such as sugar, starch, etc.)-based carbon solid acid catalyst while Amberlyst-15 resulted in significantly lower levels of conversion, demonstrating its relatively high catalytic activity for simultaneous esterification and transesterification. Moreover, as the catalyst can be regenerated, it has the potential for use in biodiesel production from oils with a high FFA content.

An efficient one-pot route to synthesize tertiary alcohol compounds using Barbier–Grignard reaction of unactivated alkyl or aryl bromides with ester in THF at 65 °C catalyzed by CuO has been developed and systematically investigated. A wide range of substituted tertiary alcohol compounds were obtained in good to high yields. The reaction is highly chemoselective. The mechanism involving the leaving group of R2O-group is discussed.

Hierarchically macroporous–mesoporous SBA-15 phosphate adsorbent was synthesized via a dual-templating approach, followed by diamino-functionalization and Fe(III) impregnation. The resulting Fe(III)-coordinated diamino-functionalized macroporous–mesoporous adsorbent possessed well-defined and interconnecting macroporous and mesoporous networks. Its maximum adsorption was 12.7 mg/g, which was 86.8% greater than that of Fe(III)-coordinated amino-functionalized mesoporous SBA-15. In the kinetic study of macroporous–mesoporous adsorbent, 92.5% of the final adsorption capacity reached in the first 1 min; and the adsorption followed the pseudo-second-order equation well, suggesting the presence of chemisorption. The pH ranging from 3.0 to 6.0 favored the high phosphate adsorption of hierarchically porous adsorbent; however, the coexistence of other anions, especially F−, retarded the adsorption.•Fe-coordinated functionalized macro-mesoporous SBA-15 was used to remove phosphate.•The P adsorption of SBA-NN-Fe-8.6 was 86.8% higher than the mesoporous SBA-NN-Fe-0.•92.5% of the adsorption capacity of SBA-NN-Fe-8.6 reached within the first 1 min.•High phosphate adsorption of SBA-NN-Fe-8.6 was recorded from pH 3.0 to 6.0.•The coexistence of anions retarded the phosphate adsorption of SBA-NN-Fe-8.6.

Polysaccharides based polyelectrolyte complex nanoparticles (PCNs) intended for use in the delivery of macromolecules were prepared by the self-assembly of deoxycholic acid hydrophobically modified chitosan (CS-DCA) core and then coated with sodium alginate (ALG) shell. The CS-DCA capable of forming nano-sized self-aggregates in medium was prepared by the grafting of DCA to CS. In order to increase the stability of nanoparticles and prevent burst release of drug in bloodstream, polyanionic ALG was coated on the surface of positively charged CS-DCA nanoparticles to form PCNs. Dynamic light scattering results revealed that the mean diameter of the PCNs was about 330 nm, larger than that of uncoated nanoparticles (~150 nm). The zeta potential was big enough to keep the stability of PCNs (−28 mV); no size change was found even upon 1 month storage. Bovine serum albumin could be easily incorporated into the PCNs with encapsulation efficiency (>44 %) and keep a sustained manner without burst release when exposed to PBS (pH 7.4) at 37 °C. These results suggested that PCNs may be a promising drug carrier for a prolonged and sustained delivery in the bloodstream.

The urchin-like Bi2S3 spheres and CuS/Bi2S3 composite nanowires have been fabricated through a soft chemical route without the assistance of any templates or surfactants. The resulting samples are characterized by scanning electron microscopy, transmission electron microscopy, powder X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, and UV-visible diffuse reflectance spectroscopy. The results demonstrate that the morphology, optical and magnetic properties of products exhibit remarkable change owing to copper modification of Bi2S3 nanostructures. Furthermore, the CuS/Bi2S3 nanostructures display high visible light photoactivities, which can be attributed to the combined effect of copper modification of Bi2S3.

A novel regioselective reaction of styrene with the prepared magnesium organoselenolates from magnesium, alkyl or aryl bromides, and selenium has been developed in one pot. The reaction catalyzed by CuI and l-proline proceeded in THF, water, and toluene. The scope and limitations of this reaction have been examined. The reaction afforded unsymmetrical selenides containing 12 new compounds in good to high yields.

We report the synthesis of ZnxCd1–xS@ZnO nanorod arrays via a facile two-step process and the implementation of these core–shell nanorods as an environmental friendly and recyclable photocatalyst for methyl orange degradation. The band gap of ZnxCd1–xS@ZnO core–shell nanorods can be readily tunable by adjusting the ratio of Zn/Cd during the synthesis. These ZnxCd1–xS@ZnO core–shell nanorods exhibit a high photocatalytic activity and good stability in the degradation of the methyl orange. Moreover, these films grown on FTO substrates make the collection and recycle of the photocatalyst easier. These findings may open new opportunities for the design of effective, stable, and easy-recyclable photocatalytic materials.

•BiOI/BiVO4 shows greatly improved photoelectrochemical water splitting capability.•Its photocurrent density achieves 3.27 mA cm2 at 1.23 V vs. RHE.•Its Faraday efficiency retains 95% after 10 h illumination.•The p–n junction is believed to play a critical role in this significant enhancement.Herein, we report an effective synthesis method of BiOI/BiVO4 p–n junction that greatly improves the performance of BiVO4 for photoelectrochemical water splitting due to a synergistic effect. The photocurrent density of BiOI/BiVO4 photoanodes achieved 3.27 mA cm2 at 1.23 V vs. RHE, which is much higher than those of pristine BiVO4 and BiOI (1.23 mA cm2 and 0.15 mA cm2 at 1.23 V vs. RHE, respectively). At 0.68 eV vs. RHE, BiOI/BiVO4 shows the maximum of applied bias photo-to-current efficiency of 0.97% at 0.68 V vs. RHE. This new BiOI/BiVO4 p–n junction not only facilitates the separation and transfer of photo-generated charges, but also expands the light absorption range, which is the origin for this synergistic effect. The BiOI/BiVO4 p–n junction materials with excellent solar water splitting capability should shed light on designing and fabricating the next-generation photocatalysts.Download high-res image (260KB)Download full-size image

•Adsorptive properties of mesoporous materials for phosphate removal are reviewed.•Common preparative methods and the resultant surface properties are provided.•The adsorptive capacities of different systems are compared.•Factors affecting phosphate adsorption are discussed.Mesoporous materials have significant potential for use as adsorbents for removal of phosphate from water. The chemical and structural properties of materials greatly affect their capacity and rate in the phosphate adsorption process. This paper reviews recent activities in the development of mesoporous materials as phosphate adsorbents. In particular, it mainly focuses on the synthesis, properties and phosphate removal efficiency of various materials with mesoporosity, including metal-coordinated amino-functionalized silicas, ammonium-functionalized silicas, metal-doped mesoporous silicas, metal oxides, metal sulfate and carbon.

Carboxyl single-walled carbon nanotubes (SWNTs) were used to construct an innovative drug delivery system by modification with chitosan (CHI) to enhance water solubility and biocompatibility. Hyaluronan (HA), as the target ligand for CD44, was bound to the CHI layer to selectively kill cancer cells. To achieve a new treatment strategy for cancer, the drug delivery system was loaded with the anticancer drug doxorubicin hydrochloride (DOX). The data showed that the system loaded with DOX with zeta potentials of 8.52 ± 0.12 mV at pH 7.4 and 12.53 ± 0.23 mV at pH 5.5 had high drug-loading efficiency, reaching 107.73 ± 0.67%. It also exhibited sustained and controlled drug-release, depending on pH; it released less than 10% at pH 7.4 but nearly 85% at pH 5.5 after 72 h. Cell viability results indicated that the drug delivery system effectively killed HeLa cells while it had lower cytotoxicity against fibroblasts. Combined histological examinations and blood property analyses demonstrated that it did not cause severe damage to vital organs in SD rats. Thus, this drug delivery system may provide a high therapeutic efficacy for cancer, while minimising adverse side effects.