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Heterostructured Bi 3 O 4 Br/α-Bi 2 O 3 nanocomposites are prepared via in situ one-step self-combustion of ionic liquids. Tetrabutylammonium bromide (TBAB) is employed to be fuel, complexing agent for ionic liquids, as well as the reactant supplying Br for the objective material. The ratio of Bi 3 O 4 Br/α-Bi 2 O 3 can be easily adjusted by controlling the amount of TBAB. The heterojunctions show higher photocatalytic ability towards both azo dye methyl orange (MO) and colorless pollutant phenol. The electron spin resonance (ESR) test and p-nitro blue tetrazolium chloride (NBT) degradation result indicate that generation amounts of superoxide anion radicals ( O 2 − ) over heterojunctions are less than that over pure Bi 3 O 4 Br. Photoelectrochemical measurements show that separation efficiencies of photo-generated electrons and holes are decreased after the combination of Bi 3 O 4 Br and α-Bi 2 O 3 . Work function test and scavenger experiments display that holes play key role for pollutant degradation and the position of holes on α-Bi 2 O 3 is lowered via hybridization. Thus, the enhanced photocatalytic activity over composites can be attributed to the position decline of α-Bi 2 O 3 valence band, thus improving the reactivity of holes in direct oxidation of pollutants. In this case, valence band position is confirmed to be more important than separation efficiency of charge carriers in affecting photocatalytic performance. [ABSTRACT FROM AUTHOR]

Abstract: A new plasmonic photocatalyst of Ag–AgI/Fe3O4@SiO2 was prepared by deposition–precipitation and photoreduction method. The catalyst exhibited efficient photocatalytic activity for the degradation of rhodamine B dye and 4-chlorophenol under visible light irradiation. The degradation rate of rhodamine B and 4-chlorophenol over Ag–AgI/Fe3O4@SiO2 was about 10 times and 4.1 times faster than that of N–TiO2, respectively. The catalyst could be easily recovered due to its paramagnetic property. X-ray diffraction, X-ray photoelectron spectroscopy and transmission electron microscope were used to characterize the catalyst. The specified photocatalytic reaction and the study of electron paramagnetic resonance verified that both the O2 − glyph name="rad" />OH radicals were the main active species in this reaction. [ABSTRACT FROM AUTHOR]

Abstract: Hydroxyapatite (Ca10(PO4)6(OH)2: HAP) was co-substituted with Ti(IV) and antibacterial ions (Ag+, Cu2+ or Zn2+) (HAPTiM), by coprecipitation and ion-exchange methods. Both HAPTiAg and HAPTiCu coated on porous spumous nickel film showed high efficiency for killing Escherichia coli and Staphylococcus aureus in the dark and under weak UVA irradiation, respectively. Moreover, their bactericidal activities were much higher than that of P25-TiO2 film. The studies of ESR revealed that not only O2 − was formed on HAPTiM, HAPTi, HAP and P25-TiO2 films under weak UVA irradiation, but also at ambient temperature without light O2 − was generated on HAPTiCu, HAPTiAg, and HAPTi. The redox couples of Cu0/Cu2+ and Ag0/Ag+ in the structure of HAPTiCu (Ag) caused the transfer of electron leading to the O2 − generation under the above conditions. The higher bactericidal activities of HAPTiM were due to the synergy of the oxidation role of the O2 − and the bacteriostatic action of antibacterial ions. The process of the damage of the cell wall and the cell membrane was directly observed by TEM, and further confirmed by the determination of potassium ion (K+) leakage from the killed bacteria. [Copyright &y& Elsevier]

Glycerol oxidation reaction (GOR) is an attractive alternative reaction for oxygen evolution reaction (OER) in the electrochemical water splitting and can be used to generate high-value products. However, the development of GOR electrocatalysts with high catalytic activity and low cost is challenging. In this research, a self-supported copper-manganese electrode (MnO 2 -CuO/CF) was developed, which attains a current density of 10.7 mA cm−2 at a low potential of 1.3 V, while yielding 1,3-dihydroxyacetone (DHA), with a selectivity of 60%. DFT calculations reveal the synergistic effect between CuO and MnO 2 , enhancing glycerol adsorption. Additionally, the overlap configuration of CuO and MnO 2 results in a lower electron density on MnO 2 , preventing further oxidation and increasing DHA selectivity. By coupling GOR and water electrolysis, the dual output of high value-added organic products and high-purity hydrogen can be realized, which provides a new idea for green hydrogen production and electrochemical synthesis of high value-added chemicals. [Display omitted] • The copper-manganese self-supported electrodes(MnO 2 -CuO/CF) was constructed. • MnO 2 -CuO/CF attains 10 mA cm−2 at 1.3 V with a selectivity of 60% for 1,3-dihydroxyacetone. • The DFT calculations revealed the mechanism of GOR on MnO 2 -CuO/CF electrode. • Overlap configuration regulates the electron density of MnO 2 , promoting the desorption of DHA. [ABSTRACT FROM AUTHOR]

Photoelectrochemical conversion of solar energy into fuels (or chemicals) is in urgent need of efficient photoanodes to drive its practical applications. Nevertheless, the development of high performance photoanode usually suffers from slow charge transfer and sluggish surface catalytic kinetics. Here, we report a surface active oxygen engineering strategy through the modification and activation of NiCo layered double hydroxide (NiCo-LDH), where the activated NiCo-LDH (NiCo-LDH-Act) captures the photogenerated holes and acts as cocatalyst for surface oxidation reactions. The as-developed BiVO 4 /NiCo-LDH-Act achieves more than 3-fold higher photocurrent density than that of pristine BiVO 4. Experimental integrated with theoretical studies further testify the bifunctional of NiCo-LDH-Act for hole transport and catalytic reactions. Moreover, the adsorbed ·OH originated from active oxygen enables efficient oxidation of glycerol to attain 1,3-dihydroxyacetone (DHA) with a productivity of 20.5 μmol cm–2 h–1 at 1.4 V vs. RHE with simultaneously producing hydrogen at the cathode. [Display omitted] ● Various cobalt-based LDHs were modified and activated on metal oxide photoanodes. ● Activated NiCo-LDH enables a 3.13-fold improvement in the performance of BiVO 4. ● Surface active oxygen originates from dehydrogenation of hydroxyl groups on LDHs. ● Photoelectrochemical oxidation of glycerol to DHA coupled with hydrogen production. ● Identification and mechanism reveal of adsorbed·OH radical intermediates. [ABSTRACT FROM AUTHOR]

Well-designed hierarchical F-BiVO 4 @NiFe-LDH photoanode with a core-shell heterostructure has been successfully fabricated by F− ions etching and in situ electrochemical synthesis of NiFe-LDH onto BiVO 4 film, which demonstrates enhanced photoelectrochemical water splitting and degrada antibiotic tetracycline hydrochloride. • F-BiVO4@NiFe-LDH photoanode has been successfully developed by surface/interface engineering. • The photoanode exhibits efficient performance in PEC water splitting coupled with degradation of organic pollutants. • Experimental studies and DFT calculation reveal a synergistic effect of F doping and NiFe-LDH cocatalyst. • This strategy can be extended to other photoelectrodes for solar energy conversion and wastewater treatment. Antibiotic resistance has become a global problem as indicated by the worldwide emergence of multidrug-resistant bacteria, which makes it an urgent demand to develop effective technologies for antibiotics removal from pharmaceutical wastewater. In this work, simultaneously removing antibiotic tetracycline from wastewater coupled with pure H 2 generation has been successfully achieved through PEC technique by using F-doped BiVO 4 @NiFe-LDH (F-BiVO 4 @NiFe-LDH) core-shell photoanode. The maximum photocurrent density of the F-BiVO 4 @NiFe-LDH photoanode at 1.23 V vs. RHE is about 6-fold that of the pristine BiVO 4 photoelectrode. Furthermore, the composite photoanode was effectively applied to the PEC degradation of tetracycline hydrochloride (TCH), superior to the reported results. An experimental-computational combination study reveals that the synergistic effect between F doping and NiFe-LDH simultaneously improves the light absorption, charge separation and charge injection efficiency of BiVO 4. This work presents a sunlight-driven, efficient and sustainable method for water splitting to produce hydrogen and new insights into wastewater treatment. [ABSTRACT FROM AUTHOR]