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Gold was loaded on several ZnO samples with different morphologies: needle-like (ZnO-n), flower-like (ZnO-f), rods (ZnO-r), and prepared by a thermal calcination process (ZnO-t). A commercial ZnO sample (ZnO-c) was also used for comparison. Bare ZnO and Au/ZnO materials were used for the photocatalytic production of H 2 from a water–ethanol solution under UV–vis irradiation ( λ > 300 nm). During the photocatalytic runs, hydrogen was generated at a constant rate for all samples, as well as CH 4 and CO. The obtained results show that bare ZnO materials were able to promote H 2 photogeneration, being ZnO-f the most efficient in terms of H 2 generation. Loading with Au, in general, increased the photoefficiency for all materials. The most active gold loaded photocatalysts were the ones with the lowest gold nanoparticle sizes: Au/ZnO-f (427 μmol h −1 g cat −1 ; 5.4 nm) and Au/ZnO-n (280 μmol h −1 g cat −1 ; 5.8 nm). The samples with largest size (Au/ZnO-r and Au/ZnO-t with 6.2 nm, and Au/ZnO-c with 12.5 nm) were not so efficient (values below 230 μmol h −1 g cat −1 ). Au/ZnO-f seems to be the most promising photocatalyst, generating the highest amount of H 2 and the lowest quantities of CH 4 and CO. It is also possible that the intricate morphology of ZnO-f may scatter the incoming light, enhancing light absorption efficiency and increasing the photoefficiency of this material. [ABSTRACT FROM AUTHOR]

Metal sulfides are a type of reduction semiconductor photocatalysts with narrow bandgap and negative conduction band potential, which make them have unique photocatalytic performance in solar-to-fuel conversion and environmental purification. However, metal sulfides also suffer from low quantum efficiency and photocorrosion. In this review, the strategies to improve the photocatalytic activity of metal sulfide photocatalysts by stimulating the charge separation and improving light-harvesting ability are introduced, including morphology control, semiconductor coupling and surface modification. In addition, the recent research progress aiming at improving their photostability is also illustrated, such as, construction of hole transfer heterojunctions and deposition of hole transfer cocatalysts. Based on the electronic band structures, the applications of metal sulfides in photocatalysis, namely, hydrogen production, degradation of organic pollutants and reduction of CO 2 , are summarized. Finally, the perspectives of the promising future of metal-sulfide based photocatalysts and the challenges remaining to overcome are also presented. [Display omitted] • Fundamental properties and synthesis methods of metal-sulfide (MS) photocatalysts are summarized. • Strategies to improve the photoactivity of MS include morphology, semiconductor coupling and surface modification. • Heterojunction and co-catalyst used to transfer of holes can prevent photocorrosion of MS photocatalysts. • The remaining challenges and future of MS based photocatalysts are reviewed and forecast. [ABSTRACT FROM AUTHOR]

[Display omitted] • TiO 2 mesocrystals were prepared by a solvothermal procedure followed by calcination. • Calcination introduced oxygen vacancies (Ov) by removal of adsorbed fluoride ions. • T600 with Ov is 4.9 times more active for acetone oxidation than uncalcined TiO 2. • Introduction of Ov optimizes light adsorption and charge carrier transfer of TiO 2. In this study, TiO 2 mesocrystal assemblies of ultrathin TiO 2 nanosheets with (0 0 1) facets were prepared by a microwave-assisted solvothermal method using tetrabutyl titanate (TBT), NH 4 F and acetic acid. The relationship between calcination temperature (300–1000 °C) and photocatalytic activity towards acetone oxidation was systematically studied. It was found that fluoride ions adsorbed on the surface were removed after calcination, generating surface oxygen vacancies (Ov). The 600 °C-calcined sample (T600) exhibited the highest photocatalytic activity towards acetone oxidation, which was 4.9 times higher than the activity of pristine TiO 2 mesocrystals. The formation of Ov not only improved the ability of light absorption, stimulated the charge carrier separation, enhanced the photocatalytic activity, but also prevented the growth of TiO 2 mesocrystals, by retarding the fusion of the neighboring TiO 2 mesocrystals, increasing anatase-to-rutile phase transformation temperature to values above 1000 °C. [ABSTRACT FROM AUTHOR]

This work focuses on the combination of multifunctional photocatalytic and adsorbent materials in a unique polymeric membrane. For this purpose, Au/TiO 2 and Y 2 (CO 3) 3 nanoparticles were immobilised onto a poly (vinylidene fluoride-hexafluoropropylene), (PVDF-HFP) membrane, and the physical-chemical characterisation of these materials was performed, as well as pollutant removal efficiency. An efficient TiO 2 functionalisation with gold nanoparticles was achieved, endowing these particles with the capability to absorb visible radiation absorption. A favourable porous structure was obtained for the membranes, with an average pore size of 4 μm, and the nanoparticles immobilisation did not alter the chemical properties of the polymeric membrane. The produced hybrid materials, including both the Au/TiO 2 and Y 2 (CO 3) 3 nanoparticles, presented an efficiency of 57% in the degradation of norfloxacin (5 mg/L) under ultraviolet radiation for 120 min, 80% under visible radiation for 300 min, and 58% in arsenic adsorption for 240 min. These membranes represent a new multifunctional platform for removing several pollutants, which may allow their incorporation in more efficient and less energy-consuming water treatment processes favouring its application, even in low energy resources countries. [Display omitted] • Synthesis of Au–TiO 2 nanocomposites with ability to absorb visible radiation. • Production of porous multifunctional Au–TiO 2 /Yttrium/PVDF-HFP membranes. • Photocatalytic and adsorptive efficiency tested in norfloxacin and arsenic removal. • Multifunctional tests performed for simultaneous photocatalysis and adsorption. [ABSTRACT FROM AUTHOR]

[Display omitted] • The recent progresses of Bi-based photocatalysts were summarized. • Strategies include defect, facet, SPR effect, heterojunctions and hierarchical structures. • Photocatalytic oxidation pathways over Bi-based photocatalyst are introduced. • The future of Bi-based photocatalysts are outlooked. Bismuth (Bi)-based photocatalysts have been attracting a lot of attention due to their visible-light-responsive properties, unique layer framework and adjustable electronic band structure. However, their photocatalytic behavior is not satisfactory, which hinders practical applications. Therefore, much research has been carried out to improve their photocatalytic performance. This review outlines the different methods and mechanisms dealing with modification of Bi-based photocatalysts. It summarizes the strategies used for enhancing the photocatalytic activity of these materials, including: (1) defect regulation, (2) exposed facet control, (3) surface plasmon resonance (SPR) effect utilization, (4) heterojunction construction, (5) hierarchical porous structure design, (6) polarization effect and (7) solid solution establishment. Also a focus is given on BiOCl photocatalysts as major examples. Their applications as oxidation and reduction photocatalysts are referred, along with detailed photocatalytic reaction mechanisms. Finally, the future prospects and challenges of Bi-based photocatalytic materials are discussed. [ABSTRACT FROM AUTHOR]

In this work, we successfully synthesized novel polymer gel beads based on functionalized iron oxide (Fe3O4), activated charcoal (AC) particles with β-cyclodextrin (CD) and sodium alginate (SA) polymer (Fe3O4/CD/AC/SA), by a simple, reproducible and inexpensive method. These beads proved to be versatile and strong adsorbents with magnetic properties and high adsorption capacity. The composites were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, vibrating sample magnetometry, adsorption at −196 °C, high resolution transmission electron microscopy, thermogravimetric analysis and point of zero charge measurements. Two dyes, two drugs and one metal were used to test the adsorption capability of the prepared polymer nanocomposite. The adsorbent showed good removal efficiencies for the studied pollutants, especially the cationic dyes and the metal, when compared to other low-cost adsorbents. The saturated adsorption capacity of Fe3O4/CD/AC/SA reached 5.882 mg g−1 for methyl violet (MV), 2.283 mg g−1 for brilliant green (BG), 2.551 mg g−1 for norfloxacin (NOX), 3.125 mg g−1 for ciprofloxacin (CPX), 10.10 mg g−1 for copper metal ion (Cu(II)). The adsorption isotherm studies showed that data fitted well with Langmuir and Temkin isotherms models. The kinetic data showed good correlation coefficient with low error function for the pseudo-second order kinetic model. The data analysis was carried out using error and regression coefficient functions for the estimation of best-fitting isotherm and kinetic models, namely: chi-square test (χ2) and sum of the squares of errors (SSE). The activation energy was found to be 47.68 kJ mol−1 for BG, 29.09 kJ mol−1 for MV, 28.93 kJ mol−1 for NOX, 4.53 kJ mol−1 for CPX and 17.08 kJ mol−1 for Cu(II), which represent chemisorption and physisorption behavior of sorbent molecules. The polymer composites can be regenerated and easily separated from aqueous solution without any weight loss. After regeneration, the Fe3O4/CD/AC/SA beads still have good adsorption capacities up to four cycles of desorption and adsorption. The results indicate that the polymer gel beads are promising adsorbents for the removal of different categories of toxicants (like dyes, drugs and metal) in single adsorbate aqueous systems. Thus, the novel Fe3O4/CD/AC/SA beads can be effectively employed for a large-scale applications as environmentally compatible materials for the adsorption of different categories of pollutants. ga1 • Fe 3 O 4 /CD/AC/SA gel beads obtained by a simple, reproducible and inexpensive method. • Dyes (MV, BG), drugs (NOX, CPX) and Cu(II) ion were efficiently adsorbed on the beads. • Excellent removal efficiencies obtained, compared to other low-cost adsorbents. • Beads can be regenerated and easily separated from solution without any weight loss. [ABSTRACT FROM AUTHOR]

Modified chicken feathers (MCFs) were used as adsorbents for the removal of Co(II), Cu(II), Fe(II) and Ni(II) heavy metal ions from water by varying pH, adsorbent concentration and time. MCFs were characterized using Fourier Transform Infrared (FTIR) spectroscopy, Scanning Electron Microscopic (SEM) analysis, Energy Dispersive X-ray (EDX) spectroscopy, Adsorption of N 2 at −196 °C, Thermogravimetric analysis (TGA) and X-ray Diffraction (XRD) analysis. The adsorption isotherm for the metal ions could be well explained by the Langmuir model. The maximum adsorption capacities were 200.0, 50.0, 43.47, and 4.85 mg/g, following the sequence: Cu(II) > Co(II) > Fe(II) > Ni(II), respectively. Removal efficiencies of Co(II), Cu(II), Fe(II) and Ni(II) ions were 98.7%, 98.9%, 98.7% and 99%, respectively, for 20 mg/L concentration. The study of the adsorption kinetics for metal ions on MCFs confirmed that the process followed a pseudo second order kinetic model in all cases. The thermodynamics showed that the adsorption processes for metal ions adsorption on MCFs were spontaneous and endothermic. MCFs exhibited a good recyclability and high adsorption efficacy after 7 cycles using a 0.1 M EDTA solution, maintaining 90% of the adsorption ability. Modification of chicken feathers enhanced the adsorption capacity of the MCFs due to the increase of hydroxyl groups in the adsorbent and the rough surface was found in SEM image. MCFs have relatively high specific surface area and good thermal stability. Unlabelled Image • Biosorption of heavy metals on chemically treated chicken feathers (MCFs). • Characterization of MCFs by FTIR, SEM , EDX, XRD, N 2 adsorption, and TG/DTG. • Sequence of maximum adsorption capacity: Cu(II) > Co(II) > Fe(II) > Ni(II). • MCFs after desorption recovered and reused up to seven cycles. • Adsorbent binding with the metal ions. [ABSTRACT FROM AUTHOR]

Nickel particles deposited on hydrothermally synthesized ceria nanorods (CeO 2 -NR) were found to be highly active and stable for CO 2 methanation. A CO 2 -to-CH 4 yield of 92% was achieved at 300 °C. The impact of various operational parameters was explored in conjunction with a thermodynamic analysis. The superior performance of Ni/CeO 2 -NR was demonstrated through a comparison with i) CeO 2 and Ni/CeO 2 commercial products, ii) various M/CeO 2 -NR lab-synthesized catalysts (M = Cu, Co, Fe), and iii) state-of-the-art literature catalysts. The results revealed that a unique combination of Ni with ceria nanorods is required for boosting the reducibility and in turn the methanation efficiency. Unlabelled Image • CeO 2 nanorods were synthesized by a facile hydrothermal method. • Ni/CeO 2 -nanorods exhibited excellent CO 2 methanation performance. • Α CO 2 -to-CH 4 yield of 92% was achieved at 300 °C. • High reducibility of Ni/CeO 2 linked to nickel-ceria nanorods interactions. • Superior methanation performance compared to most state-of-the-art Ni-based catalysts. [ABSTRACT FROM AUTHOR]

The superior photocatalytic activity of TiO 2 nanocrystals with exposed high-energy (001) facets, achieved through the use of hydrofluoric acid as a shape-directing reagent, is widely reported. However, in this study, we report for the first time the detrimental effect of surface fluorination on the photoreactivity of high-energy faceted TiO 2 nanocrystals towards NO oxidation (resulting in a NO removal rate of only 5.9%). This study aims to overcome this limitation by exploring surface defluorination as an effective strategy to enhance the photocatalytic oxidation of NO on TiO 2 nanocrystals enclosed with (001) facets. We found that surface defluorination, achieved through either NaOH washing (resulting in an improved NO removal rate of 23.2%) or calcination (yielding an enhanced NO removal rate of 52%), leads to a large increase in the photocatalytic oxidation of NO on TiO 2 nanocrystals with enclosed (001) facets. Defluorination processes stimulate charge separation, effectively retarding recombination and significantly promoting the production of reactive oxygen species, including superoxide radicals (·O 2 - ), singlet oxygen ( 1 O 2 ), and hydroxyl radicals (·OH). Both in situ diffuse reflectance infrared Fourier-transform spectroscopy and density functional theory calculations confirm the higher adsorption of NO after defluorination, thus facilitating the oxidation of NO on TiO 2 nanocrystals.

Cadmium sulfide (CdS) is a photocatalyst widely used for efficient H 2 production under visible light irradiation, due to its narrow bandgap and suitable conduction band position. However, the fast recombination of carriers results in their low utilization. In order to improve photocatalytic hydrogen production, it reports the successful introduction of metallic Cd and S vacancies on CdS nanorods (CdS NRs) by a facile in situ chemical reduction method, using a thermal treatment process. This procedure generates interfacial and polarization electric fields, that significantly improve the photocatalytic hydrogen production performance of CdS NRs in sodium sulfide and sodium sulfite aqueous solutions, under visible light irradiation (λ >420 nm). The introduction of these electric fields is believed to improve charge separation and facilitate faster interfacial charge migration, resulting in a significantly optimized catalyst, with a photocatalytic hydrogen evolution rate of up to 10.6 mmol -1  g -1  h -1 with apparent quantum efficiency (AQE) of 12.1% (420 nm), which is 8.5 times higher than that of CdS. This work provides a useful method to introduce metallic and S vacancies on metal sulfide photocatalysts to build local polarization and interfacial electric fields for high-performance photocatalytic H 2 production., (© 2023 Wiley-VCH GmbH.)

The worldwide increase in antibiotic resistance poses a significant challenge, and researchers are diligently seeking new drugs to combat infections and prevent bacterial pathogens from developing resistance. Gold (I and III) complexes are suitable for this purpose. In this study, we tested four gold (I and III) complexes, ( 1 ) chlorotrimethylphosphine gold(I); ( 2 ) chlorotriphenylphosphine gold(I); ( 3 ) dichloro(2-pyridinecarboxylate) gold (III); and ( 4 ) 1,3-bis(2,6-diisopropylphenyl)imidazole-2-ylidene gold(I) chloride, for their antibacterial, antibiofilm, antiviral, and anti-quorum sensing activities. Results reveal that 1 significantly inhibits Escherichia coli DSM 1077 and Staphylococcus aureus ATCC 6538, while 2 , 3 , and 4 only inhibit S. aureus ATCC 6538. The minimum inhibitory concentration (MIC) of 1 for S. aureus ATCC 6538 is 0.59 μg/mL (1.91 μM), and for methicillin-resistant S. aureus strains MRSA 12 and MRSA 15, it is 1.16 μg/mL (3.75 μM). For E. coli DSM 1077 (Gram-negative), the MIC is 4.63 μg/mL (15 μM), and for multi-resistant E. coli I731940778-1, it is 9.25 μg/mL (30 μM). Complex 1 also disrupts biofilm formation in E. coli and S. aureus after 6 h or 24 h exposure. Moreover, 1 and 2 inhibit the replication of two enterobacteria phages. Anti-quorum sensing potential still requires further clarification. These findings highlight the potential of gold complexes as effective agents to combat bacterial and viral infections.

A series of Cu catalysts supported on Ce1-xSmxOδ mixed oxides with different molar contents (x=0, 0.25, 0.5, 0.75 and 1), was prepared by wet impregnation and evaluated for volatile organic compounds (VOC) abatement, employing ethyl acetate as model molecule. An extensive characterization study was undertaken in order to correlate the morphological, structural and surface properties of catalysts with their oxidation activity. The optimum performance was obtained with Cu/CeO2 catalyst, which offers complete conversion of ethyl acetate into CO2 at temperatures as low as 260°C. The catalytic performance of Cu/Ce1-xSmxOδ was interpreted on the basis of characterization studies, showing that incorporation of samarium in ceria has a detrimental effect on the textural characteristics and reducibility of catalysts. Moreover, high Sm/Ce atomic ratios (from 1 to 3) resulted in a more reduced copper species, compared to CeO2-rich supports, suggesting the inability of these species to take part in the redox mechanism of VOC abatement. Sm/Ce surface atomic ratios are always much higher than the nominal ratios indicating an impoverishment of catalyst surface in cerium oxide, which is detrimental for VOC activity., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Invited for this month's cover are collaborators from the University of Porto in Portugal and KU Leuven in Belgium. The image shows that nanodiamond-TiO 2 composites can effectively degrade organic water pollutants by photocatalysis under ambient conditions. This process will reduce human impact on freshwater systems, thereby contributing to meet worldwide targets on water footprint reduction. Read the full text of the article at 10.1002/cplu.201300094., (Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)