High-calcium and high-phosphorus vanadium slag (HCPVS), a byproduct generated from pre-dephosphorization in the converter vanadium extraction process, represents a valuable vanadium resource. However, research on extracting vanadium from HCPVS remains limited. Conventional vanadium extraction techniques face substantial challenges in processing this slag, notably low vanadium conversion efficiency, which severely restricts its high-value utilization. This study systematically investigates the intrinsic mechanisms and key scientific issues impeding the efficient utilization of HCPVS by combining multiscale characterization with first-principles calculations. Several innovative findings are presented. First, vanadium-doped CaTiO3 phases were identified in HCPVS, which remain stable during roasting and leaching. These phases form when vanadium selectively substitutes for titanium in the CaTiO3 lattice during converter smelting. Second, theoretical calculations indicate that the stability of vanadium-doped CaTiO3 decreases with increasing vanadium substitution concentration. Third, the phase speciation and distribution of vanadium in roasted HCPVS were quantitatively resolved: after roasting at 850 degrees C, 45.74 wt.% of vanadium resides in vanadium-doped CaTiO3, 47.82 wt.% occurs in vanadate phases, and 6.44 wt.% is distributed in silicate phases. This work clearly elucidates the key factors limiting vanadium conversion efficiency in HCPVS and provides a theoretical foundation for developing novel processes aimed at highly efficient vanadium extraction.

Spinel is the predominant mineral phase sequestering vanadium within vanadium slag. Consequently, its oxidative decomposition is a pivotal stage in the roasting-based extraction process. This study systematically elucidates the oxidation products and elemental migration pathways of the spinel using multiple characterization techniques and thermodynamic calculations. Results indicate that the spinel mainly consists of FeV2O4, which incorporates Ti, Mn, and Cr to form a solid solution. Kinetic analysis yielded an average apparent activation energy of 241.03 kJ·mol−1 for spinel oxidation, where the observed increase in activation energy with conversion rate suggests a complex, multi-stage reaction mechanism. The spinel remains stable below 500 °C. Oxidation initiates at grain boundaries between 600 °C and 700 °C, leading to the formation of iron‑manganese vanadate and ilmenite. Above 750 °C, rapid decomposition occurs, and oxidation is nearly complete by 800 °C. At 900 °C, the roasted products comprise a spinel-like phase (43.70 wt%), iron-manganese vanadate (20.58 wt%), ilmenite (19.68 wt%), and iron oxide (8.19 wt%). Vanadium and manganese mainly accumulate in the spinel-like and iron-manganese vanadate phases, while titanium concentrates in the spinel-like phase and ilmenite. These findings provide a fundamental mechanistic foundation for optimizing industrial roasting parameters

Electrochemical carbon dioxide reduction reaction (eCO 2 RR) is an effective method for promoting the construction of a carbon circular economy. The alloyed Ni 3 ZnC 0.7 /G catalyst was prepared by pyrolyzing the bimetallic zeolitic imidazolate frameworks (ZIFs) embodied in the graphene oxide. The prepared catalyst exhibited excellent CO Faradaic efficiency (FE CO ) and reached a maximum of 99.43% (−0.95 V vs RHE), surpassing the performance of the catalyst Ni/G. During 60 hours of electrolysis, Ni 3 ZnC 0.7 /G maintained a stable current density above 30 mA cm −2 and a FE CO of over 80%. The characterization results revealed that the pure phase of Ni 3 ZnC 0.7 was formed, assisted by the porous carbon substrate, and the as-formed catalyst demonstrated a higher electrochemically active surface area in the eCO 2 RR. X-ray photoelectron spectroscopy (XPS), in situ ATR-SEIRAS, and Density functional theory (DFT) calculations suggested a facile electron transfer from Zn to Ni, and the nitrogen-doped carbon substrate significantly enhanced the electron transfer rate. The increased electronic density of Ni site in Ni 3 ZnC 0.7 /G improved the *COOH species formation, simultaneously weakening the adsorption of *CO, thereby promoting the generation of CO and suppressing the hydrogen evolution reaction.

Abstract Colloidal InP quantum dots (QDs) are promising near-infrared (NIR) materials for environmentally benign QD-sensitized solar cells (QDSCs). Yet previous studies on QDSCs have never been able to extend the light harvesting capability of InP QDs to NIR. In this work, InP QDs with an absorption onset reaching ∼750 nm were synthesized using low-reactivity indium(I) salts and phosphine precursors combined with NH4PF6-mediated in situ etching. Ligand exchange with 3-mercaptopropionic acid enabled high-density and uniform loading of these QDs on mesoporous TiO2 photoanodes. Through optimization of photoanode architecture and interfacial engineering, a record power conversion efficiency of 5.20% was achieved for InP-QDSCs. Transient absorption analysis reveals that device performance is primarily constrained by the small energetic driving force for electron injection from NIR InP QDs to TiO2, providing guidance for further development of high-efficiency InP-based QDSCs.

Converter vanadium slag (CVS) is the primary source of vanadium extraction, with roasting serving as the most critical step in the process. Consequently, a comprehensive investigation of the roasting process is essential for optimizing the efficient and high-quality utilization of CVS. This study conducts an in-depth investigation of the calcium roasting process. In-situ X-ray diffraction (XRD) analysis reveals that the spinel phase in CVS begins to decompose at 500 degrees C and it disappears at 800 degrees C. The oxygen-temperature programmed oxidation (O2-TPO) results indicate that significant oxidation of spinel phase take place accompanying with it decomposition in the temperature range of 500-700 degrees C. X-ray photoelectron spectroscopy (XPS) and thermal analysis (TG-DSC) further confirm a facile oxidation of spinel phase during roasting process, and the formation of vanadate is the key factor influencing the roasting process. XRD analysis of solid-phase simulation reaction products demonstrates that vanadium can react with various oxides in CVS to form vanadate. Electron probe microanalysis (EPMA) shows that, vanadium exists as complex compounds in both calcium and blank roasted CVS, primarily within vanadium-containing phases enriched with Fe/Ti (P1), Fe/Cr (P2), Fe/Mn (P3), Fe/V (P4), Fe/Si (P5), V/Mn (P6), and V/Ca (P7). Leaching experiments reveal that vanadium in P1 to P5 is difficult to extract. Calcium introduced during the calcium roasting process effectively suppresses the formation of P1 to P5, thereby promoting vanadium recovery. This study provides theoretical support for approaching the cleaning and high-quality utilization of CVS by calciums roasting.

Olivine phosphate cathodes are widely adopted in power and grid-scale storage owing to their intrinsic safety and structural robustness; however, LiFePO4 (LFP) is constrained by its relatively low operating voltage, leaving limited headroom for further energy-density enhancement. By contrast, LiMnPO4 (LMP) offers a higher voltage plateau and thus greater energy-output potential, yet it suffers from more severe interfacial parasitic reactions and pronounced structural/stress penalties under high-voltage operation, making high-rate capability and longterm cyclability difficult to achieve simultaneously. To elucidate the synergy between high energy density and high stability, we comparatively investigate LFP, LiMnxFe1-xPO4 (LMFP, Fe:Mn = 1:1), and LMP under an intrinsic-comparison framework. By minimizing confounding factors such as carbon coating and complex interfacial engineering, and by adopting identical electrode fabrication with comparable areal loading, an applesto-apples evaluation of the behaviors is achieved. The structural and chemical states were verified by Rietveldrefined XRD, SEM/TEM, and high-resolution XPS, confirming effective Fe/Mn solid-solution substitution in LMFP. Electrochemical performance was evaluated primarily via galvanostatic charge-discharge, enabling a systematic comparison of voltage profiles, cycling behavior, and gravimetric energy density as well as energy retention among the three cathodes. Furthermore, first-cycle potential-resolved EIS/DRT enables analysis of Li+ diffusion, polarization, and the coupled interfacial film-charge-transfer-diffusion processes, thereby elucidating the composition-driven shift of rate-limiting steps and the distinct origins of polarization along the LFP-LMFPLMP evolution. Taken together, the structural characterization, voltage-platform analysis, and kinetic evidence demonstrate that LMFP incorporates the high-voltage Mn contribution to enhance energy output while retaining LFP-like structural and interfacial reversibility, achieving a more favorable balance between energy density and cycling stability. These insights provide interpretable and transferable guidelines for composition engineering and scale-up of LMFP cathodes.

Electrochemical carbon dioxide reduction reaction (eCO(2)RR) is an effective method for promoting the construction of a carbon circular economy. The alloyed Ni3ZnC0.7/G catalyst was prepared by pyrolyzing the bimetallic zeolitic imidazolate frameworks (ZIFs) embodied in the graphene oxide. The prepared catalyst exhibited excellent CO Faradaic efficiency (FECO) and reached a maximum of 99.43% (-0.95 V vs RHE), surpassing the performance of the catalyst Ni/G. During 60 hours of electrolysis, Ni3ZnC0.7/G maintained a stable current density above 30 mA cm(-2) and a FECO of over 80%. The characterization results revealed that the pure phase of Ni3ZnC0.7 was formed, assisted by the porous carbon substrate, and the as-formed catalyst demonstrated a higher electrochemically active surface area in the eCO(2)RR. X-ray photoelectron spectroscopy (XPS), in situ ATR-SEIRAS, and Density functional theory (DFT) calculations suggested a facile electron transfer from Zn to Ni, and the nitrogen-doped carbon substrate significantly enhanced the electron transfer rate. The increased electronic density of Ni site in Ni3ZnC0.7/G improved the *COOH species formation, simultaneously weakening the adsorption of *CO, thereby promoting the generation of CO and suppressing the hydrogen evolution reaction.

Local CO2 concentration and efficient electron transfer are critical for facilitating CO2 activation. Herein, we developed a hydroxyl-rich Zn/Co layered double hydroxide (Zn2Co3(OH)10 center dot 2 H2O) via a facile solvothermal method. The electronic interaction between Zn and Co not only induces the formation of abundant oxygen vacancies but also creates electron-enriched Co sites, collectively establishing a highly synergistic catalytic center. Simultaneously, the rich hydroxyl groups on the catalyst surface enhance the local CO2 concentration and serve as a proton reservoir. Owing to this unique configuration, the catalyst achieves a high Faradaic efficiency for CO (exceeding 88%) over a wide potential window (-1.13 V to-0.73 V vs. RHE) and a current density of 50 mA cm-2. Mechanistic studies reveal that the synergistic center promotes the formation and stabilization of the key *COOH intermediate, enabling efficient CO2-to-CO conversion at a reduced overpotential. This work highlights the importance of engineering bimetallic electronic synergy in designing high-performance CO2 reduction electrocatalysts.

High-performance MnO2 for aqueous zinc-manganese batteries (AZMBs) is still predominantly produced through laboratory-scale syntheses that deliver low output and are difficult to scale, creating a persistent barrier to practical deployment. Here, we introduce a "programmable chaotic suspension electrolysis" strategy that incorporates nonlinear dynamics into the electrodeposition process to achieve macroscopic production of MnO2 with precise microstructural control. Compared with conventional synthesis routes, this approach increases the MnO2 yield by orders of magnitude. Furthermore, by regulating the aperiodic oscillations of the chaotic current, we induce abundant, tunable in situ oxygen vacancies and construct a robust γ/β intergrown tunnel framework. This distinct defect engineering significantly enhances the electrochemical activity of the material. Additionally, we establish a multi-dimensional evaluation framework that confirms the superior thermal stability of the optimized product. Coupled with Life Cycle Assessment (LCA) and Techno-Economic Analysis (TEA), the process demonstrates significant potential for reducing energy consumption and production costs. Overall, this work provides a generalizable pathway for the scalable manufacturing of high-performance electrode materials and highlights the promise of chaotic electrochemistry in constructing next-generation safe, low-cost energy storage systems.

Carbon deposition remains a formidable challenge in the practical application of methane dry reforming technology. Herein, a series of La0.95X0.05NiO3 (X = Pr, Sm, Ce) and La1-yCeyNiO3 (y = 0.3, 0.5, 0.7) mixed metal oxide catalysts were synthesized via the citric acid chelation method. The catalytic performance evaluations indicate Ce as the most effective promoter. Characterizations revealed that increasing the Ce doping level induced a structural transformation of the catalyst from a perovskite to a pyrochlore phase, elevated active oxygen species from 15.19% to 51.87%, enhanced the reducibility of NiO species and improved its capacity for CO2 activation. At a reaction temperature of 750 degrees C, the La0.95Ce0.05NiO3 catalyst yielded CH4 and CO2 conversion rates of 90.89% and 91.08%, respectively. Compared to the undoped catalyst, the carbon deposition rate was reduced by 44.5%. The La0.7Ce0.3NiO3 catalyst achieved CH4 and CO2 conversion rate of 89.43% and 92.42%, exhibiting an 83.7% decrease in carbon deposition. The optimized La0.95Ce0.05NiO3 and La0.7Ce0.3NiO3 catalysts exhibited stable catalytic performance during the 48 h durability test, with carbon deposition of 22.23% and 6.84%, respectively. The superior anti-coking performance may be attributed to active oxygen species generated during the phase transformation process, which promote CO2 activation and accelerate the gasification of deposited carbon. This work focuses on the rational design of oxide catalysts by modulating their chemical composition through doping to engineer specific crystal structures.

This coupled current offers a clean and more energy-efficient approach that facilitates Mn production and advances new electrodeposition technologies.

Efficient and energy-saving electrodeposition of manganese remains challenging due to inhomogeneous deposition and competing hydrogen evolution at cathodic interfaces. Here, we report a dynamic molecular adsorption strategy using trace thiourea derivatives to regulate interfacial ion transport and nucleation behavior, achieving spontaneous grain refinement within the electrodeposited layer. Combined computational and experimental analyses reveal that thiourea derivatives construct a dynamic adsorption layer at the electrode/electrolyte interface, increasing the nucleation overpotential. Meanwhile, the electron-donating coordination of thiourea derivatives regulates the solvation structure of Mn2+ and reduces interfacial water activity. This approach achieves spatially uniform Mn nucleation and spontaneous phase transition from metastable gamma-Mn to stable alpha-Mn with refined grains, accompanied by a reduction in average grain size to 1.129 mu m. With the methylthiourea (MTU) additive, we achieve 86.87 % current efficiency (a 4.61 % improvement) at reduced energy consumption of 4328.47 kWh t-1 (a 6.28 % reduction). Application in aqueous all-manganese batteries demonstrates an average Coulombic efficiency of 80.85 % over 30 cycles. This work proposes a molecular-level interfacial engineering strategy that enables cleaner metal electrodeposition and sustainable aqueous energy-storage applications, offering a new design paradigm for Mn metal as a clean and sustainable material.

Photoelectrochemical (PEC) devices have great potentials in the fields of photocatalysis and photoelectric conversion. Preparing nano-sized electrode materials with excellent properties through a simple and convenient method is significant in developing these devices. Here in this work, a facile one-step vapor deposition is adopted to fabricate photoelectrodes coated by tin selenides (SnSex, x = 1, 2) nanosheets films using single SnSe precursor. The chemical vapor deposition (CVD) feature during preparation process is the cause for the emergence of SnSe2. Corresponding phase formation mechanism as well as spatial phase distribution are studied. Taking advantage of deposition regularities, nanosheets composed of single phase (SnSe or SnSe2) or heterojunction (SnSe/SnSe2) are selectively in-situ grown on conductive substrate. When applied in PEC-type photo-detecting system, the one based on SnSe/SnSe2 heterojunction exhibits excellent photoresponse behaviors of high photoresponsivity (2.5 mu A mW(-1)) and specific detectivity (108 Jones) as well as noteworthy self-powered activity, superior than the counterparts based on single phase. The increased separation efficiency of photogenerated carriers under the built-in electric field at the interface of SnSe/SnSe2 heterojunction is the reason of enhanced photoresponse performances. This work may enlighten and promote the further controllable preparation of heterojunction materials with satisfied photoelectrochemical performances.

LiMnxFe1-xPO4 (LMFP) materials, with their high energy density and excellent cycle stability, are promising cathode materials for electric vehicles and other high-energy-density applications. However, the low lithium-ion diffusion coefficient and poor electronic conductivity limit the further development of LMFP. In this study, we designed a strategy involving electrostatic self-assembly and in situ graphitization to fabricate a dense LMFP@MXene@C structure with dual encapsulation of LMFP (LiMn0.6Fe0.4PO4). Owing to its high degree of graphitization, large surface area, excellent Li-ion directional transport, and dense dual encapsulation structure, the fabricated LMFP@MXene@C cathode exhibits a considerable reversible capacity (153.58 mA h g-1 after 100 cycles at 1C) with outstanding rate performance and stability (maintaining 91.26% of its capacity after 1200 cycles at 5C). According to detailed TEM, in situ XRD techniques, and system dynamics and structural stability assessments analysis, the superior electrochemical stability and Li+ transport can be attributed to the network structure formed by 2D MXene layered channels and amorphous C layers. This structure facilitates rapid electron and ion transfer, effectively providing volumetric buffering and structural protection. The dual encapsulation strategy offers a feasible approach for the preparation of exceptional electrochemical cathode materials.

This study presents an innovative approach combining suspension electrolysis and stirring techniques to precisely modulate the crystal structure and electrochemical properties of gamma-MnO2. By optimizing the concentration of suspended particles and stirring rate, a directional regulation of gamma-MnO2 crystal morphology was achieved. Compared to the conventional electrolysis in industry, the content of gamma-MnO2 increased by 8.44 % under optimal conditions, with the crystal morphology transforming from pine-needle-like to daisy-like structures, accompanied by a significant enhancement in crystallinity. The optimal suspended particle concentration was determined as 0.8 g center dot L-1, and the optimal stirring speed at 300 rpm. Under these conditions, the crystallinity of gamma-MnO2 reached 84.2 %, showing a substantial improvement compared to the control group without particle additives. Additionally, thermal stability analysis indicated that the average activation energy of the gamma-MnO2 samples was 324.65 kJ center dot mol-1, demonstrating excellent stability. Electrochemical tests further confirmed that the addition of suspended particles and stirring enhanced the mass transfer of Mn2+, lowered solution resistance and tank pressure, resulting in energy-efficient electrolysis, with the Cdl value of gamma-MnO2 reaching 0.9408F center dot m-2, indicating an increase in active sites.

Prolonging exciton lifetime in colloidal quantum dots (QDs) is crucial to their photochemical applications. Previously, this was achieved through a mechanism called thermally activated delayed photoluminescence (TADPL) for QDs surface-anchored with molecular triplet energy acceptors, in which the molecular triplets sensitized by QDs can repopulate QD-excitons through thermally activated reverse energy transfer. Here, we demonstrate a novel TADPL mechanism achieved by engineering the surface trap states of QDs. Rapid exciton trapping and thermally activated slow detrapping prolong the exciton lifetime of low-toxicity ZnSe-based QDs from the timescale of ∼10 ns to ∼100 µs. Such a long exciton lifetime allows direct engagement of QDs in diffusion-assisted energy transfer, without needing surface-anchored molecules as triplet transmitters, for solution-phase photochemical applications such as photon upconversion and [2 + 2] cycloaddition. This advantage not only greatly streamlines the design of QD-based photochemical systems but also avoids the reliability issue associated with the anchoring between QDs and molecules, as well as enabling facile tuning of the TADPL wavelength range not limited by the availability of molecular triplet acceptors.

As a sustainable energy storage technology, aqueous zinc-manganese batteries (Zn-MnO2) attract significant attention, but they still face challenges such as rapid capacity decay and poor rate performance. In this study, a prismatic MnO2-MOF-74 composite cathode material is successfully constructed through the in-situ growth of MnO2 on the Mn-MOF-74 framework. This synergistic structure significantly enhances the material's structural stability, maintaining a specific capacity of 200 mAhg(-1) after 400 cycles at 500 mA g(-1). Additionally, it improves ion diffusion kinetics, with a diffusion coefficient of similar to 1.0 x 10(-12) cm(2) s(-1) (measured by galvanostatic intermittent titration technique, GITT). This work provides an important technical pathway for developing stable, high-energy-density aqueous zinc-ion batteries (AZIBs) and advances the progress of sustainable energy storage.

Shortwave infrared (SWIR) light-driven photoinduced electron/energy transfer reversible addition-fragmentation chain transfer (PET-RAFT) polymerization holds great promise for applications such as 3D printing and transdermal photopolymerization. However, efficient SWIR-active photocatalysts remain lacking. Herein, we report the use of lead-free CuInSe2/CuInS2 core/shell quantum dots (QDs), with their absorption onset extending to 1100 nm, to drive efficient SWIR PET-RAFT polymerization. Time-resolved spectroscopy reveals that both band-edge and trap-state electrons can transfer to the RAFT agent. The relatively sluggish hole transfer, due to hole localization to copper states, can be accelerated by introducing amines as hole scavengers. The reaction exhibits well-defined characteristics of living polymerization and proceeds efficiently in the presence of a 3 mm biological tissue barrier under 1050 nm irradiation.

Electron transfer (ET) plays a crucial role in many chemical and biological reactions, as well as in optoelectronic devices. Recent studies across different systems often found the ET rates to be insensitive to the temperature, which is beyond the current theoretic framework based on Marcus theory and its modified semiclassical versions and suggests the critical role of nuclear quantum tunneling. Here we formulate a pure quantum tunneling expression of ET rate, which is dictated by the reactant-product vibration wave function overlap of a simplified single quantum mode. This model works remarkably well for describing the weak temperature dependence of ET rate from photoexcited quantum dots to their surface-anchored naphthalene diimides acceptors in both normal and inverted regions, measured from 4 to 300 K. This study underscores the crucial role of nuclear tunneling effects in charge migration at the nano/molecular scales.