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The development of high-performance visible-light photocatalysts with a tunable band gap has great significance for enabling wide-band-gap (WBG) semiconductors visible-light sensitive activity and precisely tailoring their optical properties and photocatalytic performance. In this work we demonstrate the continuously adjustable band gap and visible-light photocatalysis activation of WBG BiOIO3via iodine surface modification. The iodine modified BiOIO3 was developed through a facile in situ reduction route by applying BiOIO3 as the self-sacrifice template and glucose as the reducing agent. By manipulating the glucose concentration, the band gap of the as-prepared modified BiOIO3 could be orderly narrowed by generation of the impurity or defect energy level close to the conduction band, thus endowing it with a visible light activity. The photocatalytic assessments uncovered that, in contrast to pristine BiOIO3, the modified BiOIO3 presents significantly boosted photocatalytic properties for the degradation of both liquid and gaseous contaminants, including Rhodamine B (RhB), methyl orange (MO), and ppb-level NO under visible light. Additionally, the band structure evolution as well as photocatalysis mechanism triggered by the iodine surface modification is investigated in detail. This study not only provides a novel iodine surface-modified BiOIO3 for environmental application, but also provides a facile and general way to develop highly efficient visible-light photocatalysts. [ABSTRACT FROM AUTHOR]

We herein report a facile and general approach to modulating the band energy level of semiconductors for visible-light photocatalysis via iodide surface decoration. This strategy enables the wide-band-gap Bi2O2CO3 to possess a continuously tunable band gap and profoundly boosted visible-light photocatalytic performance for dye degradation and NO removal. [ABSTRACT FROM AUTHOR]

Development of efficient photocatalysts with both photoinduced oxidation and reduction properties is of great importance for environmental and energy applications. Herein, we report the fabrication of CeO2/g-C3N4 hybrid materials by a simple in situ co-pyrolysis method using Ce(IO3)3 and melamine as precursors. The CeO2/g-C3N4 composite catalysts possess outstanding photocatalytic activity for phenol degradation and NO removal under visible light irradiation. The degradation efficiency reaches up to 68.5 and 17.3 times higher than that of pure CeO2 and g-C3N4, respectively. Significantly, it simultaneously exhibits an enhanced hydrogen production rate, which is 1.5 times that of the pure g-C3N4. The highly enhanced photo-induced oxidation and reduction activity could be attributed to the construction of a CeO2/g-C3N4 n–n type heterojunction established by our in situ co-pyrolysis route, which enables intimate interaction across the phase interfaces; this facilitates separation and transfer of photoexcited charge carriers. This study could not only provide a facile and general approach to the fabrication of high-performance carbon-nitride-based photocatalytic materials, but also increase our understanding further on designing new hybrid composite photocatalysts for multi-functional applications. [ABSTRACT FROM AUTHOR]

The orthophosphate phosphors ABaPO4:Eu2+ (A = K, Rb) have been studied in this paper. The continuous solid-solution phases in (Kx,Rb1−x)BaPO4 have been determined and the phase structure evolution and its dependence on the K : Rb ratio have been discussed, and all the Eu2+-doped (Kx,Rb1−x)BaPO4 phosphors show a blue emission, peaking at approximately 420 nm, originating from the 4f–5d transition of Eu2+. The differences in the fine microstructure have been investigated and the effect on the photoluminescence behavior, especially the thermally stable luminescence, has been studied for this series of solid-solution phosphors. The relationship between the activation energy and thermally stable luminescence is also discussed. The compositionally optimized (Kx,Rb1−x)BaPO4:Eu2+ phosphor can be potentially applied in phosphor-converted white light-emitting diodes (w-LEDs). [ABSTRACT FROM AUTHOR]

Transformation of carbon dioxide and nitrate ions into urea offers an attractive route for both nitrogen fertilizer production and environmental remediation. However, achieving this transformation under mild conditions remains challenging. Herein, we report an efficient photoelectrochemical method for urea synthesis by co-reduction of carbon dioxide and nitrate ion over a Cu 2 O photocathode, delivering urea formation rate of 29.71±2.20 μmol g -1  h -1 and Faradaic efficiency (FE) of 12.90±1.15 % at low external potential (-0.017 V vs. reversible hydrogen electrode). Experimental data combined with theoretical calculations suggest that the adsorbed CO* and NO 2 * species are the key intermediates, and associated C-N coupling is the rate-determining step. This work demonstrates that Cu 2 O is an efficient catalyst to drive co-reduction of CO 2 and NO 3 - to urea under light irradiation with low external potential, showing great opportunity of photoelectrocatalysis as a sustainable tool for value-added chemical synthesis., (© 2024 Wiley-VCH GmbH.)

Exposure of anisotropic crystal facets allows the directional transfer of photoexcited electrons (e - ) and holes (h + ), for spatial charge separation. High-index facets with a high density of low-coordinated atoms always serve as reactive catalytic sites. However, preparation of multi-facets or high-index facets is highly challenging for layered bismuth-based photocatalysts. Herein, we report the preparation of unprecedented eighteen-faceted BiOCl with {001} top facets and {102} and {112} oblique facets via a hydrothermal process. Compared to the conventional BiOCl square plates with {001} top facets and {110} lateral facets, the eighteen-faceted BiOCl has highly enhanced photocatalytic activity for H 2 evolution and hydroxyl radicals ( . OH) production. Theoretical calculations and photodeposition results disclose that the of eighteen-faceted BiOCl has a well-matched {001}/{102}/{112} ternary facet junction, which provides a cascade path for more efficient charge flow than the binary facet junction in BiOCl square plates., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A central issue in understanding photo-redox catalysis is the facet-dependent charge movement behaviors that include bulk charge separation, surface charge transfer and interfacial charge migration. To get in-depth insight into these complicated processes steered by different exposing facets, herein BiOCl with exposed (001) and (010) facets engaged as the model are investigated. The BiOCl-(010) and BiOCl-(001) single-crystalline sheets are separately synthesized via hydrothermal and hydrolysis routes. In contrast to BiOCl-(010), BiOCl-(001) demonstrates highly promoted photo-redox performance for H 2 generation and degradation of pollutants. The facet-dependent charge movement behaviors were surveyed by surface photovoltage spectroscopy (SPV), transient photocurrent, linear sweep voltammetry, continuous wavelength photocurrent, and electrochemical impedance spectrum (EIS). All the photoelectrochemical and photoelectric measurement results reflect that BiOCl-(001) exhibits superior charge separation and migration efficiencies in the whole charge movement process than the BiOCl-(010). Besides, a higher charge carrier density (3.1-fold enhancement) was also observed for BiOCl-(001) compared to BiOCl-(010). Our current work is expected to further our understanding on facet-dependent charge movement behaviors and offer new insight into design of high-performance photocatalytic/photoelectrochemical materials., (Copyright © 2017 Elsevier Inc. All rights reserved.)