Search Results (427)

A novel catalyst, Tm₂FeSbO₇, was synthesized by employing the solid-phase high-temperature sintering method, and, for the first time, it was utilized to create a Z-type heterojunction with BiYO₃. A direct Z-scheme Tm₂FeSbO₇/BiYO₃ heterojunction photocatalyst (TBHP) was successfully produced by employing the ball-milling technique. X-ray diffraction analysis results indicated that Tm₂FeSbO₇ crystallized in a cubic pyrochlorestructure which owned the Fd-3m space group, with a unit cell parameter of 10.1769 Å, whereas BiYO₃ displayed a fluorite structure in the Fm-3m space group, with a unit cell parameter of 5.4222 Å. The Mossbauer spectrum of Tm₂FeSbO₇ showed that Fe³⁺ ions might locate at octahedral sites. The measured bandgap widths for the TBHP, Tm₂FeSbO_7, and BiYO₃ were 2.14 eV, 2.21 eV, and 2.30 eV, respectively. Multiple experimental results demonstrated that the TBHP exhibited a higher valence band ionization potential, a narrower band gap width, and a higher removal efficiency of the sulfamethoxazole (SMX) compared with the Dy₂TmSbO₇/BiHoO₃ heterojunction photocatalyst. Under visible-light irradiation (VISLI) of 115 min, the TBHP showcased exceptional photocatalytic elimination performance; therefore, the elimination rate of the SMX and the total organic carbon (TOC) mineralization rate reached 99.51% and 98.10%, respectively. In contrast to single-component Tm₂FeSbO₇, BiYO_3, or conventional nitrogen-doped titanium dioxide (N-TiO₂) catalyst, the TBHP exhibited removal efficiency enhancement for degrading the SMX by 1.17 times, 1.31 times, or 4.06 times. Simultaneously, the matching mineralization rate for removing the TOC density by employing the TBHP was 1.20 times, 1.34 times, or 4.73 times higher than that by employing Tm₂FeSbO₇, BiYO₃, or conventional N-TiO₂. Above experimental results indicated that the mineralization efficiency for removing TOC density by employing the TBHP was higher than that by employing Tm₂FeSbO₇, BiYO₃, or N-TiO₂. Radicals trapping experiments and the electron paramagnetic resonance spectroscopy results revealed that hydroxyl radicals, superoxide anions, and photoinduced holes were the primary active species during the catalytic elimination course of the SMX by employing the TBHP under VISLI. The results demonstrated that the direct Z-scheme TBHP, which was developed in this study, exhibited the maximal removal efficiency for degrading the SMX in contrast to Tm₂FeSbO₇, BiYO₃, or N-TiO₂. Additionally, the possible elimination routes and elimination mechanisms of the SMX were proposed. Therefore, an important scientific foundation for developing high-performance heterojunction catalysts was established. Full article

The concurrent challenges of environmental pollution and energy scarcity necessitate advanced sustainable technologies. Photocatalytic fuel cells (PFCs) offer a promising route by coupling pollutant degradation with energy recovery. However, the synergistic interplay between anode intrinsic properties and macroscopic polarization effects remains inadequately understood. Herein, a BiOBr-doped TiO₂ nanotube array photoanode with engineered oxygen vacancies was developed to construct a synergistically enhanced PFC system. XPS, EPR, and DFT analyses confirm the formation of oxygen vacancies and favorable band bending, inducing an internal electric field that markedly promotes charge separation and interfacial reaction kinetics. As a result, the charge separation efficiency is enhanced by approximately fourfold relative to pristine TiO₂ nanotube arrays. Under the combined action of the internal electric field and self-bias-induced polarization field, photogenerated electrons and holes undergo directional transport and effective utilization. The optimized PFC achieves 78% sulfamethoxazole degradation within 180 min, representing a 1.38-fold improvement. Degradation pathways and toxicity evolution were further elucidated using LC–MS and Fukui function analysis, highlighting the critical role of electric field-driven charge regulation in high-performance PFCs. Full article

The effect of Mn addition on the structural, dielectric, ferroelectric, and mechanical properties of Bi_0.5Na_0.5TiO₃ (BNT) and 0.94(Bi_0.5Na_0.5TiO₃)–0.06(BaTiO₃) (BNT–BT) ceramics was systematically investigated under identical processing conditions. Powders were calcined at 750 °C for 2 h and 900 °C for 2 h, followed by sintering at 1060 °C for 5 h. Mn contents of 0.5 and 5 mol% were selected to represent low-level substitution and near-saturation regimes. XRD confirmed single-phase perovskite formation within laboratory detection limits, while Raman spectroscopy revealed Mn-induced lattice distortions. Low Mn addition (0.5 mol%) enhanced densification and improved remanent polarization in BNT–BT (Pr = 33.5 μC/cm²). In contrast, 5 mol% Mn promoted grain coarsening, increased porosity, and reduced functional performance. Mechanical properties evaluated using two-parameter Weibull statistics showed composition-dependent variations in characteristic hardness and elastic modulus. The results demonstrate that Mn-doping effects depend strongly on both dopant concentration and host-lattice structural state, distinguishing beneficial substitution from defect-saturation behavior in lead-free BNT-based ceramics. Full article

We employed density functional theory (DFT) to investigate the effect of tungsten (W) doping on the crystal structure, electronic properties, and optical response of Bi₂MoO_6−xW_xO₆. The results show that W doping retains the Aurivillius orthorhombic lattice structure while inducing localized distortions. All doping systems retain semiconductor characteristics with a band gap ranging from 2.11 to 2.26 eV. The valence band is mainly composed of O-2p orbitals, while the conduction band consists of Mo-4d and W-5d states. As W doping increases, the influence of W-5d states near the conduction band edge intensifies, modulating the electronic structure. Optical calculations show that W doping shifts the absorption edge and allows for precise adjustment of the absorption threshold in the visible light range. These findings provide insight into how W doping affects the electronic and optical properties of γ-Bi₂MoO₆ and offer a theoretical basis for improving Bi₂MoO₆-based photocatalytic materials. Full article

A high-entropy strategy has emerged as a promising approach to enhance the functional properties of piezoelectric ceramics for biomedical applications. For this reason, we have designed two novel high-entropy ceramics, (Bi_1/2Na_1/2)(Zr_1/3Sn_1/3Ti_1/3)O₃(BNZST) and (Bi_1/2Na_1/2)(Zr_1/4Sn_1/4Hf_1/4Ti_1/4)O₃(BNZSHT), which were synthesized via a two-step solid-state reaction. The phase structure, surface morphology, biocompatibility, and in vitro bioactivity were assessed. The results showed both ceramics adopted perovskite structures. BNZST and BNZSHT ceramics had relatively even crystallite sizes and element distribution, as well as achieving piezoelectric (d₃₃ ≥ 78 pC/N) properties. In vitro tests confirmed a high relative cell growth rate (RSG, >80%) after co-culturing BNZST or BNZSHT ceramic with murine fibroblasts L929 for more than 3 days. In particular, the surface with electric charge enhanced L929 with more extensive, widespread, and dense proliferation for the BNZST ceramic compared to ceramics without BNZST or unpolarized BNZST. The above indicated that multi-element doping and entropy stabilization established a novel pathway for developing a high-entropy bio-piezoelectric ceramics with high biocompatibility and bioactivity, providing the possibility for their use in bone repair materials. Full article

Ionic liquid (IL) N-methyl-N′-1-(4-t-butylphenylphosphinyl)butylimidazolium bis(trifluoromethylsulphonyl) imide was used for the first time as an ion carrier in membrane systems to selectively transport Au(III), Pt(IV), and Pd(II) ions. Au(III), Pd(II), and Pt(IV) were transported from HCl solutions utilizing a polymer inclusion membrane (PIM) with cellulose triacetate as the support, o-nitrophenyl pentyl ether as the plasticizer, and ionic liquid as the mentioned ion carrier. The modifications of source and receiving aqueous phase compositions are examined. High selectivity for Au(III) using the ionic liquid in the membrane was achieved at elevated HCl concentrations (≥0.5 M). When a 0.010 M KI solution was used as the receiving phase and a membrane with the optimal composition was applied, the extraction of Au(III) ions reached a maximum recovery rate of 93%. Moreover, PIM studies showed that carrier molecules doped in the membrane creates complexes with the Au(III) ion with a molar ratio of 1:1. The extractability of Au(III) through PIMs exceeded that of other metal ions, with the selectivity of transported metal ions ranked as follows: Au(III) >> Pt(IV), Pd(II). The recovery factors for gold, platinum, and palladium ions after 6 h of transport were 94%, 8%, and 1%, respectively. Full article

Metal oxides such as TiO₂, ZnO, and BiVO₄ have emerged as pivotal materials for renewable energy technologies owing to their versatile electronic, optical, and catalytic properties. This review highlights the importance of bridging experimental investigations with Density Functional Theory (DFT) to deepen the understanding of structure–property relationships in these systems. Experimental approaches provide critical insights into synthesis strategies, performance evaluation, and sustainability, whereas DFT offers predictive power at the atomic scale by elucidating electronic structures, reaction mechanisms, and defect dynamics. The synergy of these methods enables the rational design of advanced materials for photocatalysis, solar cells, and energy storage applications. Looking ahead, research opportunities lie in the development of doped and heterostructured metal oxides, the integration of machine learning for accelerated material discovery, and the implementation of in situ/operando studies that capture time-resolved phenomena. By making the bridge between experiment and theory, significant progress can be achieved toward sustainable and efficient energy solutions. Full article

The influence of Zn²⁺, Ca²⁺ and Co²⁺ doping on the thermal, structural, morphological, and magnetic characteristics of CdBi_0.1Fe_1.9O₄ nanoparticles synthetized via the sol–gel technique and calcined at 300, 600, 900 and 1200 °C was investigated. Thermal analysis revealed the initial formation of metallic glyoxylates up to 300 °C, followed by their decomposition into metal oxides and subsequent ferrite formation. X-ray diffraction revealed that the ferrites were poorly crystallized at lower temperatures, whereas at higher calcination temperatures all nanocomposites exhibited well-crystalized ferrites coexisting with the SiO₂ matrix, except for the Co_0.1Cd_0.9Bi_0.1Fe_1.9O₄@SiO₂ nanocomposite, which formed a single, well-defined crystalline phase. Atomic force microscopy images revealed spherical ferrite particles encapsulated within an amorphous layer, with particle size, surface area, and coating thickness influenced by both the type of dopant ion and the calcination temperature. The structural parameters estimated by X-ray diffraction, as well as the magnetic characteristics, were strongly influenced by the dopant type and thermal treatment. These results demonstrate that the structural and magnetic characteristics of CdBi₀.₁Fe₁.₉O₄ ferrites can be effectively tuned through controlled doping and calcination, providing insights for the design of tailored functional applications. Full article

Bismuth-based semiconductors have emerged as a promising class of visible-light-responsive photo(electro)catalysts for environmental remediation owing to their tunable electronic structures, moderate band gaps, and relatively low toxicity. The stereochemically active Bi³⁺ 6s² lone pair and strong Bi–O orbital hybridization tailor valence-band states, enabling enhanced utilization of the solar spectrum and favorable charge-carrier dynamics. In addition, layered, perovskite-like, and aurivillius-type crystal frameworks generate internal electric fields that are advantageous for photoelectrochemical (PEC) operation. This review critically examines advances from 2015 to 2025 in the design, synthesis, modification, and environmental applications of bismuth-based photo(electro)catalysts, with particular emphasis on PEC systems for pollutant degradation. Major material families, including bismuth oxides, oxyhalides, oxychalcogenides, chalcogenides, perovskite-like oxides, and complex metal oxides, are discussed in relation to their structure–property–performance relationships. Key synthesis strategies, such as solid-state, sol–gel, hydro/solvothermal, microwave-assisted, spray pyrolysis, and electrodeposition methods, are compared with respect to morphology control, defect chemistry, and electrode integration. Performance-enhancing approaches, including elemental doping, oxygen-vacancy engineering, and the rational design of type-II, p–n, Z-scheme, and S-scheme heterojunctions, are critically assessed. Practical considerations related to stability, scalability, and techno-economic constraints are highlighted. Finally, current challenges and future directions toward durable and application-ready bismuth-based PEC technologies are outlined. Full article

Rechargeable zinc–air batteries (ZABs) are still impeded by the intrinsically sluggish kinetics of oxygen reduction and evolution reactions (ORR/OER) and by the instability or prohibitive price of state-of-the-art noble metal catalysts. Metal–organic frameworks (MOFs) have recently emerged as versatile sacrificial templates for next-generation air–cathode electrocatalysts. By programming pyrolytic or chemical conversion pathways, MOFs can be quantitatively transformed into hierarchically porous, heteroatom-doped carbon scaffolds that embed uniform metal, alloy, or metal-oxide nanodomains. The resulting architectures couple metallic conductivity with molecular-scale active site tunability, delivering exceptional ORR/OER activity, stability, and mass transport properties. This review critically examines the most recent advances in MOF-derived electrocatalysts for ZABs, establishing quantitative structure–composition–performance relationships across mono-, bi-, and multi-metallic systems. Emphasis is placed on deciphering how framework topology, metal–ligand coordination, and post-synthetic parameters dictate the density, electronic structure, and accessibility of surface-active moieties during catalyst evolution. We further dissect engineering strategies that enhance intrinsic activity via electronic modulation, bolster durability through encapsulation effects, and optimize hierarchical porosity for rapid O₂/water transport. This article concludes by outlining unresolved challenges and future research directions, including atomically precise active site construction, multi-scale compositional control, long-term reversibility under realistic ZABs cycles, scalable and green synthesis, providing a roadmap for translating MOF-derived catalysts from laboratory curiosities to commercially viable air–cathode materials. Full article

A ceramic anode made of Sb-doped SnO₂ and coated with a photoactive BiPO₄ layer was tested for the (photo)electrochemical oxidation of three commonly used pharmaceuticals: atenolol, ibuprofen, and norfloxacin. Light-pulsed chronoamperometry showed that the photoanode responded immediately to illumination. The application of light and current enhanced degradation for all compounds when treated separately. Ibuprofen and norfloxacin exhibited higher degradation than mineralization, which demonstrates their persistent nature. Electric current was essential to achieve efficient degradation and mineralization, demonstrating the effectiveness of the electrochemical approach. For multicomponent mixtures, applying light resulted in higher mineralization compared to dark conditions at low operation currents (0.2 A). At higher currents (0.4–0.8 A), the contribution of light was partially masked by the enhanced electrochemical production of hydroxyl radicals. The analysis of individual compounds within the mixture revealed significant improvements in degradation under light exposure. Overall, these results demonstrate the potential of the Sb-doped SnO₂ ceramic photoanode as a cost-effective and promising alternative to commercial materials for treating pharmaceutical contaminants. Full article

In this study, the synergistic effects of Fe doping and oxygen vacancies on the structural, electronic, and optical properties of Bi₄O₅Br₂, as well as their influence on the photocatalytic CO₂ reduction mechanism, were systematically explored through first-principles calculations. The results reveal that Fe-doped, oxygen-defective, and Fe–Vo co-modified Bi₄O₅Br₂ systems exhibit excellent thermodynamic and dynamic stability. Oxygen vacancies introduce defect states near the Fermi level, narrowing the band gap and enhancing charge localization and CO₂ adsorption, while Fe doping induces strong spin polarization and introduces Fe 3d impurity levels that effectively couple with O 2p orbitals, promoting charge transfer and visible-light absorption. The coexistence of Fe dopants and oxygen vacancies produces a significant synergistic effect, forming a continuous energy-level bridge that enhances charge separation and broadens the light absorption range. Gibbs free energy analyses further demonstrate that the Fe–Vo–BOB system exhibits the lowest energy barriers and the most favorable thermodynamics for CO₂-to-CO conversion. This study provides deep insight into the defect–dopant synergy in Bi₄O₅Br₂ and offers valuable theoretical guidance for engineering highly efficient visible-light-driven photocatalysts in solar energy conversion and environmental remediation. Full article

High electrostrain, excellent thermal stability, and low hysteresis are critical requirements for advanced high-precision actuators. However, simultaneously achieving these synergistic properties in lead-free ferroelectric ceramics remains a significant challenge. In this work, a targeted B-site doping strategy was employed to develop novel lead-free (0.99-x)BaTiO₃-xBaZrO₃-0.01Bi(Zn_2/3Nb_1/3)O₃ (BT-xBZ-BZN, x = 0–0.2) ceramics. Systematic investigation identified optimal Zr⁴⁺ substitution at x = 0.1, which yielded an outstanding combination of electromechanical properties. For this optimal composition, a high unipolar electrostrain (S_max = 0.11%) was achieved at 50 kV/cm, accompanied by an ultra-low hysteresis (H_S = 1.9%). Concurrently, a large electrostrictive coefficient (Q₃₃ = 0.0405 m⁴/C²) was determined, demonstrating excellent thermal robustness with less than 10% variation across a broad temperature range of 30–120 °C. This superior comprehensive performance is attributed to a composition-driven evolution from a long-range ferroelectric to a pseudocubic relaxor state. In this state, the dominant electrostrictive effect, propelled by reversible dynamics of polar nanoregions (PNRs), minimizes irreversible domain switching. These findings not only present BT-xBZ-BZN (x = 0.1) as a highly promising lead-free candidate for high-precision, low-loss actuator devices, but also provide a viable design strategy for developing high-performance electrostrictive materials with synergistic large strain and superior thermal stability. Full article

Supercapacitors based on mixed metal oxides are being developed as potential devices for large-scale energy storage applications with physical flexibility, thanks to their low cost and good electrochemical performance. This work demonstrates a novel approach to enhancing the electrochemical performance of bismuth–cerium oxide BiCeO₃ (BC) through thiourea doping. The incorporation of sulfur, confirmed by EDS, induced significant structural modifications, including a reduction in crystallite size from 42.5 nm to 34.8 nm and the emergence of new diffraction planes (002) and (222) in XRD patterns. These changes, indicative of successful lattice doping, yielded a more nanostructured morphology with increased active surface area and a 20% reduction in the optical band gap. Electrochemically, the thiourea-doped BiCeO₃ (BCT) electrode delivered a marked improvement, exhibiting a specific capacitance of 150 F·g⁻¹ at 25 mV·s⁻¹, a 17.2% increase over the pure BiCeO₃ (128 F·g⁻¹). Furthermore, BCT demonstrated superior rate capability and a 43% reduction in overall impedance, underscoring enhanced charge transfer kinetics and ionic conductivity. The synergy between sulfur-induced structural defects, increased electroactive surface area, and improved electronic structure establishes thiourea doping as an effective strategy for developing high-performance BiCeO₃-based supercapacitors. Full article

A novel Z-scheme Dy₂TmSbO₇/BiHoO₃ heterostructure photocatalyst was synthesized with the ultrasound-assisted solvothermal method. The Dy₂TmSbO₇/BiHoO₃ heterojunction photocatalyst (DBHP) reflected wonderful separation efficiency of photogenerated electrons and photogenerated holes owing to the efficient direct Z-scheme heterojunction structure characteristic. The lattice parameter and the bandgap energy of the Dy₂TmSbO₇ were 10.52419 Å and 2.58 eV, simultaneously, the lattice parameter and the bandgap energy of the BiHoO₃ were 5.42365 Å and 2.25 eV, additionally, the bandgap energy of the DBHP was 2.32 eV. Above results indicated that DBHP, Dy₂TmSbO₇ or BiHoO₃ possessed an excellent ability for absorbing visible light energy, therefore, DBHP, Dy₂TmSbO₇ or BiHoO₃ owned superior photocatalytic activity for degrading the sulphamethoxypyridazine (SMP) under visible light irradiation. The removal rate of the SMP after visible light irradiation of 135 min with the DBHP was 99.47% for degrading the SMP during the photocatalytic degradation (PADA) process, correspondingly, the removal rate of the total organic carbon (TOC) concentration after visible light irradiation of 135 min with the DBHP was 98.02% for degrading the SMP during the PADA process. The removal rate of the SMP after visible light irradiation of 135 min with the DBHP was 1.15 times, 1.29 times or 2.60 times that with Dy₂TmSbO₇, BiHoO₃ or nitrogen-doped TiO₂ (N-T). Therefore, the DBHP displayed higher photocatalytic activity for degrading the SMP under visible light irradiation compared with Dy₂TmSbO₇, BiHoO₃ or N-T. Specifically, the mineralization rate for removing the TOC concentration during the PADA process of the SMP with the DBHP was 1.18 times, 1.32 times or 2.79 times that with Dy₂TmSbO₇, BiHoO₃ or N-T. In addition, the stability and reusability of the DBHP were systematically evaluated, confirming that the DBHP owned potential applicability for degrading the antibiotic pollutant, which derived from the practical industrial wastewater. Trapping radicals experiments and the electron paramagnetic resonance measurement experiments were conducted for identifying the reactive radicals, such as the hydroxyl radicals (•OH), the superoxide anions (•O₂⁻) and the photogenerated holes (h⁺), which were generated with the DBHP for degrading the SMP during the PADA process under visible light irradiation, as a result, the •O₂⁻ possessed the maximal oxidative capability compared with the •OH or the h⁺. Above results indicated the degradation mechanism and the degradation pathways which were related to the SMP. In conclusion, this study makes a significant contribution for the development of the efficient Z-scheme heterostructure photocatalysts and provides a key opinion to the development of the sustainable remediation method with the view of mitigating the antibiotic pollution. Full article