F- regulate the preparation of polyhedral BiVO4 enclosed by High-Index facet and enhance its photocatalytic activity

Highly efficient removal and real-time visual detection of fluoride ions using ratiometric CAU-10-NH2@RhB: Probe design, sensing performance, and practical applications

The extensive use of fluoride in agriculture, industry, medicine, and daily necessities has raised growing concerns about fluoride residue. To date, real-time visual detection and efficient removal of fluoride ions from water remain greatly desirable. Herein, nano-CAU-10-NH2@RhB is introduced as a ratiometric fluorescent probe and efficient scavenger for the intelligent detection and removal of fluoride ions. CAU-10-NH2@RhB is readily obtained through one-pot synthesis and exhibits high sensitivity and selectivity for real-time fluoride ion detection, with a naked-eye distinguishable color change from pink to blue. A portable device for point-of-care testing was developed based on color hue analysis readout using a smartphone. A quantitative response was achieved across a wide concentration range, with a detection limit of 54.2 nM. Adsorption experiments suggest that nano-CAU-10-NH2@RhB serves as an efficient fluoride ion scavenger, with a fluoride adsorption capacity of 49.3 mg/g. Moreover, the mechanistic study revealed that hydrogen bonds formed between fluoride ions and amino groups of CAU-10-NH2@RhB are crucial for the detection and adsorption of fluoride ions. This analysis platform was also used for point-of-care quantitative visual detection of fluoride ions in food, water, and toothpaste.

Sulfide Oxidation on Ladder-Type Heteroarenes to Construct All-Acceptor Copolymers for Visible-Light-Driven Hydrogen Evolution

Conjugated polymers (CPs) have recently gained increasing attention as photocatalysts for sunlight-driven hydrogen evolution. However, they suffer from insufficient electron output sites and poor solubility in organic solvents, severely limiting their photocatalytic performance and applicability. Herein, solution-processable all-acceptor (A1 -A2 )-type CPs based on sulfide-oxidized ladder-type heteroarene are synthesized. A1 -A2 -type CPs showed upsurging efficiency improvements by two to three orders of magnitude, compared to their donor-acceptor -type CP counterparts. Furthermore, by seawater splitting, PBDTTTSOS exhibited an apparent quantum yield of 18.9% to 14.8% at 500 to 550 nm. More importantly, PBDTTTSOS achieved an excellent hydrogen evolution rate of 35.7 mmol h-1  g-1 and 150.7 mmol h-1  m-2 in the thin-film state, which is among the highest efficiencies in thin film polymer photocatalysts to date. This work provides a novel strategy for designing polymer photocatalysts with high efficiency and broad applicability.

Boosted photocatalytic performance of OVs-rich BiVO4 hollow microsphere self-assembled with the assistance of SDBS

In this study, monoclinic phase bismuth vanadate (BiOV₄) photocatalyst with unique hollow microsphere morphology was successfully prepared by a hydrothermal method in the existence of sodium dodecyl benzene sulfonate (SDBS). The prepared photocatalysts were characterized by X-ray diffraction (XRD), scanning electron (SEM) and X-ray photoelectron spectrometer (XPS) and UV-vis diffuse reflectance spectroscopy (UV-vis DRS). Experimental results show that SDBS definitely changes the microstructure of BiVO₄, which is allocated to the template role of SDBS in the preparation process. Moreover, the hydrothermal treatment time is also of crucial importance in affecting the structure and morphology of the photocatalysts, and the optimal hydrothermal treatment time for the formation of hollow microsphere is 24 h. Furthermore, the feasible growth mechanism for hollow microsphere was elaborated. Enriched oxygen vacancies (OVs) are introduced into BiOV₄ prepared with SDBS, largely elevating the separation efficiency of photo-generated charges. Under visible light irradiation, the photocatalytic activities of BiOV₄ for destruction of rhodamine (RhB) were evaluated. The photocatalytic degradation rate constant of RhB on the 3SBVO is 2.23 times of that on the blank BiOV₄ as the mass ratio of SDBS/BiOV₄ is 3 %. Photocatalytic degradation mechanism of BiVO₄ toward detoxification of organic pollutants was presented.

Two-Step Process of a Crystal Facet-Modulated BiVO4 Photoanode for Efficiency Improvement in Photoelectrochemical Hydrogen Evolution

The photoactivity of nanoporous bismuth vanadate (BiVO₄, BVO) photoanodes that were fabricated by a two-step process (electrodeposition and then thermal conversion) in photoelectrochemical (PEC) hydrogen (H₂) evolution can be enhanced about 1.44-fold by improving the constitutive ratio of (111̅), (061), and (242̅) crystal facets. The PEC characterization was carried out to investigate the factors altering the performance, which revealed that the crystal facet modulation could improve the photoactivity of the BVO photoanodes. In addition, the orientation-controlled BVO thin-film electrodes are introduced as evidence that the present crystal facet modulation is the positive effect for BVO photoanodes in PEC. The investigation of energy band structures and interfacial charge carrier dynamics of the BVO photoanodes reveals that the crystal facet modulation could result in a shorter lifetime of charge carrier recombination and larger band bending at the interface between BVO and electrolytes. This outcome could improve the charge separation and charge transfer efficiencies of BVO photoanodes, promoting the efficiency of PEC H₂ evolution. Moreover, this crystal facet modulation can combine with co-catalyst decoration to further improve the solar-to-hydrogen efficiency of BVO photoanodes in PEC. This study presents a potential strategy to promote the PEC activity by crystal facet modulation and important insights into the interfacial charge transfer properties of semiconductor photoelectrodes for the application in solar fuel generation.

Graphene oxide coupled high-index facets CdZnS with rich sulfur vacancies for synergistic boosting visible-light-catalytic hydrogen evolution in natural seawater: Experimental and DFT study

Constructing photocatalysts with high activity and anti-photocorrosion is a key to harvesting hydrogen energy from seawater efficiently. Herein, graphene oxide closely coupled high-index facets CdZnS with rich sulfur vacancies (Vs-CZS@GO) has been successfully synthesized via one-pot sulfidation accompanied pyrolysis. DFT calculation confirmed the delicate surface/interface/defect engineering endowed high-index facets Vs-CZS@GO with a lower ΔG_H* value and significant charge transfer behavior for efficient H₂-generation. The synergistic effect of sulfur vacancy, high-index facets, and tightly coupling interface not only enhanced intrinsic active sites and carrier separation efficiencies, but also greatly promoted H₂ evolution rate and stability. Consequently, Vs-CZS@GO displayed a significantly high H₂-generation rate of 23.2 mmol∙g^-1∙h^-1 in natural seawater under visible-light irradiation, which is up to 82% of that in pure water. This work provides deeply insight into the synergistic regulation of electronic structure for exposed high-index facets photocatalysts via defect engineering and interface engineering for synergistic boosting visible-light-to-H₂ evolution.

Morphology Effect of Bismuth Vanadate on Electrochemical Sensing for the Detection of Paracetamol

Morphology-control, as a promising and effective strategy, is widely implemented to change surface atomic active sites and thus enhance the intrinsic electrocatalytic activity and selectivity. As a typical n-type semiconductor, a series of bismuth vanadate samples with tunable morphologies of clavate, fusiform, flowered, bulky, and nanoparticles were prepared to investigate the morphology effect. Among all the synthesized samples, the clavate shaped BiVO₄ with high index facets of (112), (301), and (200) exhibited reduced extrinsic pseudocapacitance and enhanced redox response, which is beneficial for tackling the sluggish voltammetric response of the traditional nanoparticle on the electrode surface. Benefiting from the large surface-active area and favorable ion diffusion channels, the clavate shaped BiVO₄ exhibited the best electrochemical sensing performance for paracetamol with a linear response in the range of 0.5–100 µmol and a low detection limit of 0.2 µmol. The enhanced electrochemical detection of paracetamol by bismuth vanadate nanomaterials with controllable shapes indicates their potential for applications as electrochemical sensors.

Structure, morphology and photocatalytic performance of europium doped bismuth vanadate

Europium-doped bismuth vanadate EBVO-x (0≦x≦7) with different crystalline phases have been successfully synthesized via a simple one-pot hydrothermal method. X-ray diffractometer, Raman scattering and Scanning electron microscope revealed that the...