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As one of the high-capacity anodes in lithium-ion batteries (LIBs), silicon oxide (SiOx) has attracted wide attention due to its high theoretical capacity, low cost, and proper working voltage. However, the huge volume change and the intrinsic poor conductivity of SiOx still hinder the practical applications. How to address the issues is the focus of current research. In this work, firstly, hydrogen passivated Si nanosheets (Si6H6) were prepared from Zintl phase CaSi2, then, two-dimensional Ag nanoparticle modified SiOx/C nanocomposite was prepared via a facile complex redox reaction between Si6H6 and AgNO3-aniline complexing agent. In this design, aniline was served as carbon sources, and Si6H6 could be transformed to SiOx by AgNO3 in mild solution condition. The obtained Ag modified SiOx/C (SiOx/C-Ag) electrode exhibited high specific capacity (550 mAh·g−1 at 0.6 A·g−1), superior rate, and cycling performance when served as anode for LIBs. [ABSTRACT FROM AUTHOR]

Photocatalytic water splitting for hydrogen (H2) generation is a potential strategy to solve the problem of energy crisis and environmental deterioration. However, powder-like photocatalysts are difficult to recycle, and the agglomeration of particles would affect the photocatalytic activity. Herein, a direct Z-scheme CdS/WO3 composite photocatalyst was fabricated based on carbon cloth through a two-step process. With the support of carbon cloth, photocatalysts tend to grow uniformly for further applications. The experimental results showed that the H2 yield of adding one piece of CdS/WO3 composite material was 17.28 μmol/h, which was 5.5 times as compared to that of pure CdS-loaded carbon cloth material. A cycle experiment was conducted to verify the stability of the as-prepared material and the result demonstrated that the H2 generation performance of CdS/WO3 decreased slightly after 3 cycles. This work provides new ideas for the development of recyclable photocatalysts and has a positive significance for practical applications. [ABSTRACT FROM AUTHOR]

In combination of a facile and scalable solvothermal method and solid-phase reduction reactions, a novel two-dimensional black TiO2 − x nanosheet (TiO2 − x NS) with high specific surface area of 108 m2 g−1 and nearly total solar spectral absorption capability have been successfully prepared. With careful characterizations, the novel TiO2 − x NS showed enhanced electrochemical performance and visible-light photocatalytic activity than those of their white TiO2 nanosheet (TiO2 NS) precursors. The black TiO2 − x NS electrode delivered a reversible specific capacity of 160 mA h g−1 even after cycling at 0.5 C (1 C = 190 mA h g−1) for 300 times, which was significantly higher than the corresponding white TiO2 NS electrode (104 mA h g−1). Meanwhile, the TiO2 − x NS also exhibited enhanced ability of visible-light photocatalytic hydrogen production than that of the white TiO2 NS. It is expected that making white TiO2 NS into black ones is an effective way to design the photocatalysts with visible light response and the anodes with long lifetime and high rate performance in lithium ion batteries. The novel black TiO2 − x NS could find potential applications in the field of environmental management and energy storage and conversion. [ABSTRACT FROM AUTHOR]

A simple calcination approach was performed to synthesize layered K3Ti5NbO14/g-C3N4 (TNCN) composites, in which g-C3N4 was formed both within the interlayers and on the surface of N-K3Ti5NbO14. The photocatalytic activity of samples was evaluated by the visible-light photocatalytic degradation of rhodamine B (RhB). It was found that TNCN composite with a proper mass ratio of N-K3Ti5NbO14 to g-C3N4 exhibited the rapid rate of charge separation and high efficiency of light harvesting due to the synergetic effects of layered heterojunction and N doping, leading to an excellent photocatalytic activity. Especially, the in situ intercalated mono-layered g-C3N4 nanosheets can significantly increase the contact area between K3Ti5NbO14 layers and g-C3N4 nanosheets for efficient charge transfer across the interface, showing the greater effect on the enhanced photocatalytic activity. The active species trapping experiments and ESR measurements were carried out to evaluate the contribution of the active species in this photocatalytic degradation process. It was revealed that both superoxide radicals (·O2−) and holes (h+) are the main active species, while hydroxyl radicals (·OH) made a minor contribution to the photocatalytic degradation of RhB. [ABSTRACT FROM AUTHOR]

Li1.6Mn1.6O4 is a representative ion sieve material that is used to recover lithium from salt brines and bitterns owing to its high lithium ion adsorption capacity reaching 11.9–44 mg g−1. However, manganese dissolution during acid treatment hinders the industrial application of the material. For investigating the mechanism of manganese dissolution, the precursor Li1.6Mn1.6O4 and ion sieve H1.6Mn1.6O4 were prepared and characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), chemical content analyses, diffuse reflectance infrared Fourier-transform spectroscopy (DRIFTS), and X-ray photoelectron spectroscopy (XPS). The results of XRD, SEM, and FT-IR showed that the bulk phase of Li1.6Mn1.6O4 retained the spinel structure, whereas the lattice diminished during acid treatment. The results of chemical content analyses showed that the bulk phase of Li1.6Mn1.6O4 contained a few trivalent manganese atoms and that the mean valence of manganese in the material increased during acid treatment. DRIFTS and XPS exhibited that the surface of Li1.6Mn1.6O4 was mostly full of tetravalent manganese and retained the spinel structure during acid treatment. In the proposed mechanism of manganese dissolution, an electron of trivalent manganese in the bulk phase transfers to the surface and is captured by tetravalent manganese within the acidic environment. Then, tetravalent manganese is converted to bivalent manganese after acquiring sufficient electrons, and dissolution occurs simultaneously. [ABSTRACT FROM AUTHOR]

Abstract Proton conducting solid oxide fuel cells (SOFC) show great potential to be applied in electricity generation at intermediate temperature range, attracting the efforts of developing cathode material to further improve the power density by promoting the oxygen reduction reaction. An A-site deficient layered perovskite (PrBa) 0.95 (Fe 0.9 Mo 0.1) 2 O 5+δ (PBFM) is synthesized as cathode material for BaCe 0.7 Zr 0.1 Y 0.2 O 3 (BCZY) based SOFC. A nanostructured composite electrode is fabricated by infiltrating another cobalt-based perovskite oxide of Sm 0.5 Sr 0.5 CoO 3-δ into PBFM porous structure aiming at improving the overall catalytic reaction towards oxygen reduction. After confirming the chemical compatibility between these two materials, the electrochemical performances of the single cells are measured. With loading amount of 10% Sm 0.5 Sr 0.5 CoO 3-δ Nanoparticles, a peak power density of 532 mW cm−2 is achieved at 700 °C comparing with 359 mW cm−2 for bare PBFM electrode. A short-term stability confirms the durability of this composite electrode in practical working conditions. Highlights • A novel Layered Perovskite Cathode is evaluated for proton-conducting SOFCs. • 10. wt% Sm 0.5 Sr 0.5 CoO 3–δ is the most optimized content among all cathodes. • At 700 °C, a maximum power density of 532 mWcm−2 is obtained. [ABSTRACT FROM AUTHOR]

The construction of Z-scheme heterostructures using matching band semiconductors is an effective strategy for producing highly efficient photocatalysts. In this study, MgIn 2 S 4 (MIS) was grown in situ on In 2 O 3 microrods created with an In-based MOF material (In-MIL-68) as a template to successfully establish a unique MIS-In 2 O 3 heterojunction with a well-matched Z-scheme interface charge transfer channel. Tetracycline (TC) as a typical antibiotic was chosen as the target pollutant to evaluate the photocatalytic activity. After 120 min of visible light irradiation, the MIS-In 2 O 3 -(10:1) material had the greatest photocatalytic degradation activity of tetracycline with 96.55%, which was 2.39 and 4.26 times that of MIS and In 2 O 3 , respectively. The improved photocatalytic activity is attributed to the in situ growth of MIS on In 2 O 3 , forming a Z-scheme heterojunction at the interface, which not only increases the specific surface area, exposes the abundant active site, and improves light utilization but also facilitates the migration and separation of photogenic carriers. The photocatalytic degradation products of TC were detected by liquid chromatography-mass spectrometry (LC-MS), and a preliminary degradation pathway was proposed. Radical capture experiments and ESR analysis confirmed that the main active species were holes (h + ), superoxide radicals ( • O 2 - ), and superoxide and hydroxyl radicals ( • OH). Finally, combined with band position analysis, this study proposes a direct Z-scheme heterojunction mechanism to improve the photocatalytic degradation of tetracycline in MIS under visible light.

It has been rarely reported the morphological control of derivatives of metal-organic frameworks (MOFs) in hydrothermal conditions for photocatalytic applications. We report here a family of highly efficient composite photocatalysts composed of terephthalic acid/terephthalate (TPA) ligand and TiO 2 with various morphologies (e. g., nanoparticles, nanosheets, and nanorods). The composites are synthesized by a simple one-step hydrothermal method in various solvents (i. e., H 2 O, HF, H 2 SO 4 , HCl, and HNO 3 ) using Ti-based MOF (MIL-125(Ti)) as precursor. The formation mechanism of composite materials with different morphological features is discussed. Impressively, the composite of TiO 2 nanoparticles/TPA synthesized using H 2 O as solvent under hydrothermal condition exhibits the highest photocatalytic H 2 activity among the studied materials, with a photocatalytic H 2 production rate of 6.38 mmol g -1  h -1 , which is approximately 7.5-fold higher than pure TiO 2 (Degussa, P25) and prominent apparent quantum efficiency (AQE) of 65 % at 365 nm. Furthermore, the mechanism of boosted photocatalytic H 2 production is discussed., (© 2023 Wiley-VCH GmbH.)

Introducing piezoelectric materials with the built-in electric field caused by mechanical force has been confirmed as an effective strategy to boost the separation efficiency of photoexcited charge carriers that determines the photocatalytic performance. In this study, we introduced Bi 4 Ti 3 O 12 with superior piezoelectric properties into BiVO 4 -Bi 4 V 2 O 10 materials to synthesize a 2D Bi 4 Ti 3 O 12 -BiVO 4 -Bi 4 V 2 O 10 photocatalyst via a facile hydrothermal method. Compared with bare BiVO 4 , the Bi 4 Ti 3 O 12 -BiVO 4 -Bi 4 V 2 O 10 piezo-photocatalytic activity towards Cr(VI) removal and oxygen evolution is boosted remarkably under both illumination and ultrasound treatments. The promoted photocatalytic activity can be ascribed to the accelerated photoexcited carrier separation efficiency driven by the polarization electric field and the synergy effect in the heterostructure. This work provides a simple and sustainable strategy for the design and development of piezo-photocatalysts with high photoredox activity capacity.

Bismuth vanadate (BiVO 4 ) is a promising photocatalyst for water pollution degradation and photocatalytic oxygen evolution. In this work, we prepared 2D/2D BiVO 4 -Bi 4 V 2 O 10 heterostructure with tight interfacial contact via a facile one-step hydrothermal process. The crystal structure and morphology of the samples could be easily regulated by changing the pH values of the solution. The BiVO 4 -Bi 4 V 2 O 10 heterostructure exhibited an enhanced photodegradation rate of Cr(VI) and oxygen evolution that of bare BiVO 4 , indicating that the synergistic effect and the interfacial fusions between BiVO 4 and Bi 4 V 2 O 10 can effectively promote the migration and separation rate of photoexcited charge carriers.

Herein, we report a one-dimensional (1D) S-doped K 3 Ti 5 NbO 14 @TiO 2 (STNT) core-shell heterostructured composite with an enhanced photocatalytic degradation activity under visible light, which was prepared by a simple reassembly-calcination method using thiourea as the S source. The anisotropically shaped rods are favorable for the rapid transport of photogenerated charge carriers. The substitution of Ti 4+ by S 6+ is primarily incorporated into the lattice of the TiO 2 shell so as to create an intra-band-gap state below the conduction band (CB) position, giving rise to Ti-O-S bonds and thus the visible light response. The presence of electron-deficient S atoms is of benefit to the decreased recombination rate of photogenerated electrons and holes by capturing electrons (e - ). Meanwhile, a tight close interface between K 3 Ti 5 NbO 14 and TiO 2 was formed to achieve a nano-heterojunction structure, leading to the fostered separation of its interfacial photogenerated electrons and holes. The visible-light-driven photocatalytic degradation of methylene blue (MB) by STNT composites is higher than that by pure K 3 Ti 5 NbO 14 , owing to the synergistic effects of S doping and heterojunction. A possible photocatalytic mechanism was proposed with a reasonable discussion. This work may provide an insight into constructing highly efficient core-shell photocatalysts used toward sustainable environmental remediation and resource shortages.

Li 1.6 Mn 1.6 O 4 is a representative ion sieve material that is used to recover lithium from salt brines and bitterns owing to its high lithium ion adsorption capacity reaching 11.9-44 mg g -1 . However, manganese dissolution during acid treatment hinders the industrial application of the material. For investigating the mechanism of manganese dissolution, the precursor Li 1.6 Mn 1.6 O 4 and ion sieve H 1.6 Mn 1.6 O 4 were prepared and characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), chemical content analyses, diffuse reflectance infrared Fourier-transform spectroscopy (DRIFTS), and X-ray photoelectron spectroscopy (XPS). The results of XRD, SEM, and FT-IR showed that the bulk phase of Li 1.6 Mn 1.6 O 4 retained the spinel structure, whereas the lattice diminished during acid treatment. The results of chemical content analyses showed that the bulk phase of Li 1.6 Mn 1.6 O 4 contained a few trivalent manganese atoms and that the mean valence of manganese in the material increased during acid treatment. DRIFTS and XPS exhibited that the surface of Li 1.6 Mn 1.6 O 4 was mostly full of tetravalent manganese and retained the spinel structure during acid treatment. In the proposed mechanism of manganese dissolution, an electron of trivalent manganese in the bulk phase transfers to the surface and is captured by tetravalent manganese within the acidic environment. Then, tetravalent manganese is converted to bivalent manganese after acquiring sufficient electrons, and dissolution occurs simultaneously.