Although urban excavated soil (UES) has considerable potential for producing engineered building materials via slag-based cementitious systems, how to break the unique “card house” structure of UES, promote the hydration reaction of systems, and further enhance strength of products remains an urgent issue to be resolved in current research. Herein, the blocks were prepared using UES and ground granulated blast furnace slag, with the incorporation of alkali activators and high-performance superplasticizer (HPS), and the critical role of HPS was systematically investigated in hydration reaction of system. When the contents of HPS and UES were 0.9% and 70%, respectively, the compressive strength of blocks reached 44.46 MPa after 28 d of curing, which was 36.0% increase compared with the control group without HPS. More importantly, the strength grade of blocks increased from MU30 to MU40. Furthermore, mechanism studies indicated that HPS might effectively break “card house” structure of UES and release the encapsulated water molecules through electrostatic repulsion and steric hindrance effects, which further ensured continuous progress of hydration reaction and promoted the formation of more C-(A)-S-H gels. This study could provide a practical reference and theoretical support for exploring the sustainable valorization of UES toward producing engineered building materials in the future.

Heterogeneous catalysts with natural surface-frustrated Lewis pairs (FLPs) offer a promising alternative to artificial FLP systems for CO2 activation(,) owing to their high density and uniform spatial distribution of surface FLP sites. However, such catalysts often suffer from limited reactivity due to suboptimal Lewis acidity-basicity and insufficient stability caused by abundant undercoordinated surface atoms. Herein, Ag-modulated FLP sites (Cu & centerdot;& centerdot;& centerdot;S) are constructed using CuInSnS4 nanosheets with intrinsic FLPs for enhanced photocatalytic CO2 methanation. Comprehensive characterization and theoretical calculations demonstrate that the more ionic character of Ag-S bonds results in elevated electron density on coordinated S sites, leading to an enhanced Lewis basicity. The modified FLPs significantly enhance the polarization of CO2 molecules, thereby more effectively facilitating photogenerated electron injection into the LUMO of CO2 and enhancing the photocatalytic CO2 reduction activity. Moreover, the moderately amplified surface Lewis acidity prevents the overstabilization of *CO intermediates, achieving a near-ideal thermodynamic balance between CO desorption and *CHO formation, which favors selective CH4 production. Concurrently, the introduction of Ag significantly reduces the antibonding state occupancy of CuInSnS4, thereby markedly enhancing its photostability. This work offers a rational strategy for enhancing the reactivity and stability of heterogeneous photocatalysts with natural surface FLPs based on atomic-scale modulation of Lewis acid-base properties.

The catalytic performance of transition metal oxides is strongly influenced by the crystallographic orientation of their exposed facets, which determines the concentration and reactivity of surface lattice oxygen. In this study, facet-engineered MnO2 nanomaterials were designed to elucidate the role of lattice oxygen in photothermal catalytic oxidation of volatile organic compounds (VOCs). Toluene was selected as a model aromatic VOCs due to its chemical inertness and environmental relevance. Among the investigated samples, MnO2 with predominantly exposed {001} facets (MnO2-A) exhibited superior photothermal activity, achieving 99.4 % toluene mineralization, outperforming MnO2 with {1-1-1} (MnO2-B) and {010} (MnO2-C) facets. Comprehensive characterization revealed that MnO2-A possessed the highest surface lattice oxygen concentration, enhanced oxygen migration dynamics, and excellent light-to-heat conversion efficiency. Under illumination, the generation and mobility of active oxygen species were further promoted, thereby accelerating deep oxidation of toluene. Density functional theory (DFT) calculations confirmed that the {001} facet significantly lowers the energy barrier for oxygen activation compared with other facets. In-situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) further verified the critical role of lattice oxygen in facilitating complete mineralization pathways. This work highlights the facet-dependent lattice oxygen chemistry in MnO2 and provides fundamental insights into the design of advanced photothermal catalysts for efficient VOCs abatement.

Photocatalytic CO2 reduction to hydrocarbon fuels is a promising strategy to alleviate energy crises and achieve carbon neutrality, where photocatalysts with visible and near-infrared (Vis-NIR) light response can utilize lowenergy photons to further improve catalytic activities. However, efficient and selective production of C3 products by C2-C1 coupling process in Vis-NIR region is still challenging. Here we prepare Pd/MoWO hybrids by H2 spillover process with three-active-sites (Mo-W-Pd) by coupling Pd nanoparticles (NPs) and Mo sites doped W18O49 with oxygen vacancies (OVs). Pd/MoWO hybrids realize CO2 reduction for propionic acid (CH3CH2COOH) in Vis-NIR region with a high yield rate of 82.5 mu mol g-1h-1, an electron-based selectivity of 76.0 %, and apparent quantum efficiency of 2.0 % at 700 nm irradiation. In-situ experiments and theoretical calculations reveal that OVs neighboring Mo-W sites of Mo-W-Pd sites promote *CO-*CO coupling reaction, then Pd sites of Mo-W-Pd sites further induce C2-C1 (*CH3CH2 + *COOH) coupling process to favor the formation of propionic acid. This work provides a promising avenue for C3 products photosynthesis by low-energy photon utilization.

The effective activation of oxygen species through the interface coupling effect of catalysts to achieve photo-thermal toluene mineralization remains a major challenge. Herein, a p-n heterojunction catalyst composed of Co3O4 and Fe2O3 with strong interfacial coupling effect was rationally synthesized to overcome the intrinsic limitations, thereby achieving efficient photothermal mineralization of toluene. Under full-spectrum irradiation (350 mW/cm2), the Fe2O3/Co3O4 (0.15-FCO) p-n heterojunction achieved a toluene conversion rate of 99.72% and a CO2 yield of 87.94%, outperforming individual oxides. Comprehensive structural analysis show that the heterojunction formation elongated and weakened the Co-O bond induced by Fe2O3, thereby exposing Co3+ sites and promoting the generation of oxygen vacancies. Benefiting from interfacial coupling effect triggered by electronic modulation, 0.15-FCO enhances the adsorption and activation of O2 and toluene as further corroborated by DFT calculations. Besides, the appropriate band potentials of the p-n heterojunction facilitated charge carrier migration and activation of molecular oxygen. The results of in-situ DRIFTS further demonstrate that the incorporation of Fe2O3 promotes the oxidative conversion of intermediates on Co3O4 through interfacial charge transfer and sustaining active oxygen species generation. Overall, this study highlights that strengthening interfacial coupling in oxide materials is a viable strategy for efficient photothermal VOCs oxidation.

Heterostructured compositions of semiconducting photocatalysts can substantially enhance the separation of photogenerated charges due to their improved interphase transfer by heterojunction. In this study, Bi2WO6/ TiO2-N heterostructures were successfully prepared via the hydrothermal method using visible light-active TiO2-N nanoparticles of anatase phase as the starting material and solutions of Bi(NO3)3 and Na2WO4 as the precursors of Bi2WO6. A ratio between components was varied in a wide range to find the optimum for enhanced activity and stability of the heterostructure. The mechanism of Bi2WO6 nucleation at the presence of TiO2-N nanoparticles was studied using XRD, high-resolution TEM, EDX, and XRF analyses, whereas the electrochemical impedance spectroscopy was employed to explain the synergistic effect of composite system. The optimized Bi2WO6/TiO2-N composition containing 21 wt% of Bi2WO6 was further decorated with Fe species (0.1 wt%) to boost the visible-light activity. Photocatalytic ability of designed multicomponent Fe/Bi2WO6/TiO2-N photo-catalyst was evaluated in the degradation of acetone and formaldehyde vapor under blue light. In all cases, Fe-decorated Bi2WO6/TiO2-N heterostructure exhibited higher photocatalytic performance and provided much faster air purification compared to single-component TiO2-N photocatalyst that confirms a strong potential of its application for visible light-driven degradation of organic micropollutants in air.

The pursuit of value-added products via the photocatalytic reduction of atmospheric CO2 is largely thwarted by the kinetically sluggish adsorption and activation of low-concentration CO2 on conventional single active sites. Herein, we construct oxygen vacancies (OVs)-mediated Cu and W synergistic active sites within a CuWO4 photocatalyst via a facile hydrothermal strategy to steer the efficient conversion of atmospheric CO2, which achieves an impressive CO production yield of 19.5 mu mol g(-1) and 100% CO selectivity under ambient air condition. Experimental characterizations and theoretical calculations unveil that Cu and W sites bridged by OVs play synergistic roles: Cu sites promote the adsorption of CO2 and the rate-determining protonation step (*CO2 -> *COOH) via enhanced electron injection, while W sites further boost CO desorption by weakening *CO-surface interactions. This study not only elucidates the synergistic role of defect-induced dual metal sites but also provides a rational paradigm for designing highly active photocatalysts toward atmospheric CO2 utilization.

Conventional methods often construct heterojunctions with lattice mismatch and disordered interfaces, suppressing interfacial charge-transfer and weakening photocatalytic activity. Although epitaxial construction could obtain lattice-matched heterojunctions and then boost their carrier separation, constructing such structures under mild conditions remains challenging. Herein, we successfully prepare a lattice matched NaBiO3/Bi2O2CO3 (NBO/BOC) of 95.8 % by a facile bicarbonate (HCO3-)-triggered in-situ epitaxial strategy, which removes 98.2 % metronidazole, representing an 8.25-fold enhancement over the HCO3--free control, with an apparent reaction rate constant of 0.004 min-1. Detailed characterizations and experiments results demonstrate that this high removal activity derives from the highly lattice-matched of NBO/BOC heterojunction. That is, the lattice-matched heterointerface in NBO/BOC ensures efficient Z-scheme band coupling and enhances interfacial charge transfer under the coordination of the built-in electric field, boosting photocatalytic degradation activity of the pollutant. These findings demonstrate a sustainable strategy that leverages an inherent wastewater component to self-construct efficient photocatalytic heterojunctions for pollutant degradation.

Although photothermal catalysis offers a promising pathway for converting CO2 into high-value fuels toward carbon neutrality, the limited ability of catalysts to adsorb and activate CO2 remains a critical bottleneck for achieving high product yield and selectivity. Herein, we successfully constructed Ru nanoparticles-modified Co3O4 ultrathin nanosheets enriched with frustrated Lewis pairs (FLPs, Co2+-oxygen vacancy) that achieve an outstanding CH4 production rate of 32.15 mmol g-1 h-1 and a selectivity of 99.21% under full-spectrum irradiation. Characterization results reveal that Ru NPs effectively enhance the formation of FLPs on Co3O4 and promote H2 dissociation. In addition, theoretical calculations indicate that FLPs on 8-Ru/Co3O4 decrease the adsorption energy of CO2 from-0.118 to-0.775 eV, and Ru NPs reduce the reaction activation energy from 46.91 to 32.97 kJ & sdot;mol-1. Finally, the results of in-situ DRIFTS demonstrate that Ru NPs and FLPs interfacial synergy lower the activation barriers of key intermediates and accelerate hydrogenation kinetics, ultimately enabling efficient and selective CO2 methanation. This work provides insights for enhancing CO2 adsorption and activation to achieve efficient photothermal CO2 methanation.

Although solar-driven self-Fenton systems enable sustained in-situ production of highly oxidative center dot OH, their activity is limited by the low efficiency of H2O2 production and activation. Furthermore, the effective degradation of microplastics (MPs) as persistent aquatic pollutants remains a major environmental challenge. Herein, we construct a Se-doped CuInZnS (Se-CIZS) self-Fenton system with sulfur vacancy (Sv)/Cu(I) dual active sites, enabling high yields of H2O2 (3054.4 mu M center dot g-1 center dot h-1) and center dot OH (177.5 mu M center dot g-1 center dot h-1) under the irradiation of visible light. The high concentration of H2O2 and center dot OH ensures a mass loss rate of 34.25 +/- 1.54% and an increase in the carbonyl index by 1.62 times for PE MPs. Detailed characterizations demonstrate that Sv site can efficiently adsorb and activate O2, and stabilize *OOH intermediate for the enhancement of H2O2 generation. Meanwhile, the electron-rich Sv can accelerate the regeneration of Cu(I) sites, thereby activating H2O2 confined in the local microenvironment of the dual sites and avoiding diffusion-induced invalid decomposition. Dual-site catalyst design exhibits great potential for efficient and sustainable microplastic removal via spontaneous self-Fenton systems, while offering a novel paradigm for addressing global MPs pollution and environmental sustainability.

Visible-light photocatalytic activation of peroxymonosulfate (PMS) is a promising strategy for treating refractory organic pollutants. In this study, a novel nitrogen-doped TiO2/Ti3C2 MXene composite (N-TiO2/Ti3C2) was synthesized via an impregnation-calcination method using cetyltrimethylammonium bromide (CTAB) as the nitrogen source. N-doping effectively narrowed the bandgap of TiO2, while the highly conductive Ti3C2 MXene served as an electron-transfer platform, thereby synergistically enhancing light absorption and charge carrier separation. The N-TiO2/Ti3C2 exhibited a Brunauer-Emmett-Teller surface area of 35.86 m2/g, approximately 1.94 times higher than that of the undoped TiO2/Ti3C2, due to CTAB intercalation-induced structural regulation. Under LED visible light, the N-TiO2/Ti3C2/PMS system achieved 98.5% of rhodamine B degradation within 100 min and 81.3% of tetracycline degradation within 40 min, with good stability over a wide pH range (3.1-10.0). Mechanistic studies identified that sulfate radicals (SO4 center dot-), singlet oxygen (1O2), and holes (h+) were the dominant reactive species. LC-MS analysis elucidated the degradation pathways of rhodamine B and tetracycline. This study presents an efficient MXene-based photocatalyst for PMS activation, offering a promising strategy for wastewater treatment.

The electrocatalytic nitrate reduction reaction (NO3RR) offers a sustainable route for nitrate-contaminated wastewater remediation and ammonia (NH3) synthesis, yet its industrial implementation is bottlenecked by the lack of high-performance electrocatalysts. Spinel zinc ferrite (ZnFe2O4) has emerged as a promising candidate due to its tunable electronic structure and robust chemical stability, but its catalytic potential is severely constrained by weak nitrate activation capability and insufficient active sites. Herein, we report a Cu-doped ZnFe2O4 electrocatalyst synthesized via a solvothermal approach, wherein Cu doping in-situ induces the formation of oxygen vacancies (OVs), constructing a synergistic catalytic system. The OVs act as localized nucleophilic centers to strengthen NO3− adsorption, while adjacent Cu sites with upshifted d-band centers enhance electronic coupling with NO3− antibonding orbitals. This dual mediation optimizes reactant adsorption, promotes the breaking of N–O bonds, and reduces the energy barrier of the rate-determining step, thereby steering kinetics toward efficient NH3 synthesis. As a result, under optimized conditions (−0.7 V vs. RHE, pH = 6, 1000 mg/L NO3−), the catalyst achieves an NH3 yield rate of 531.78 μg h−1 cm−2, surpassing pristine ZnFe2O4 by 52.08%. Furthermore, the electrochemical double-layer capacitance (Cdl) reaches 25.54 mF/cm2, substantially exceeding the 4.65 mF/cm2 of the undoped sample and indicating a marked increase in active site density. This work demonstrates that the synergistic engineering of heteroatom doping and OV introduction is an effective strategy for designing high-performance NO3RR electrocatalysts, holding great potential for sustainable NH3 synthesis and nitrate-contaminated wastewater remediation.

During photocatalytic emerging organic contaminants degradation, bismuth oxyhalides typically exhibit limited exciton dissociation, resulting predominantly in the generation of 1O2 that is insufficient for deep oxidation of pollutants. Although constructing lattice-matched bismuth oxyhalide-based heterojunctions represents an effective strategy to enhance exciton separation and reactive oxygen species generation, achieving such constructions under mild synthetic conditions remains a challenge. Here, we successfully synthesize a lattice-matched BiO2-x/BiOCl (BO/BOC) heterojunction of 99.63% using a simple light-triggered in situ growth strategy in NaCl solution, which degrades 95.6% bisphenol A (BPA), representing a 4.79 fold enhancement over the NaCl-free control. Besides, BO/BOC-2 causes more severe degradation of low-density polyethylene (LDPE) than BiO2-x and BiOCl, as evidenced by pronounced morphological damage and the formation of oxygen-containing groups (O─H, C═O) in LDPE. Detailed characterization and experimental results indicate that this high photocatalytic activity stems from the built-in electric field (IEF) at the in situ grown BO/BOC Z-scheme heterojunction interface, which promotes the dissociation of excitons into carriers and the generation of ·O2 - and ·OH. This study provides a feasible strategy for the rational design of Z-scheme heterojunctions, highlighting the crucial role of interface engineering in regulating exciton dynamics and promoting charge separation to enhance the photocatalytic performance.

The crystal-phase-dependent oxidation of formaldehyde (HCHO) over MnO2 remains insufficiently understood in indoor air purification. Herein, the MnO2 with different crystal phases (delta-MnO2, alpha-MnO2, and epsilon-MnO2) was synthesized to establish a phase-structure-activity relationship for efficient HCHO mineralization at room temperature. Correspondingly, the optimal 98.07% conversion of HCHO could be achieved, and the maximum mineralization rate for CO2 reached 88% for delta-MnO2 in 30 min. Structural analyses confirmed their distinct architectures, with delta-MnO2 exhibiting the highest Mn4+/Mn3+ ratio, the largest amount of chemisorbed oxygen, and the lowest oxygen desorption temperature, reflecting superior redox cycling and oxygen activation. The results of in situ DRIFTS tests revealed a minimized accumulation of dioxymethylene and formate intermediates on the surface of delta-MnO2, consistent with accelerated oxidation kinetics. Besides, DFT calculations further indicated the strongest HCHO adsorption and highest charge transfer over MnO2, which intrinsically promotes the deep oxidation of HCHO. This work elucidates the decisive role of crystal-phase regulation in adjusting redox processes for room-temperature formaldehyde mineralization.

Although iron oxide-based catalysts have drawn much attention as eco-friendly materials for photocatalytic peroxymonosulfate (PMS) activation, their catalytic activity remains constrained by inefficient charge separation. Herein, a γ/α-phase hematite (Fe2O3) homojunction with a low contact barrier was developed, which showed efficient photogenerated charge separation and very highly catalytic activity for PMS activation under light irradiation. The optimized γ/α-phase hematite homojunction (γ/α-500) catalyst activating PMS achieved a superior metronidazole degradation rate of 0.021 min-1 under light irradiation, which was 1.90 and 2.63 times higher than those of single-phase γ-Fe2O3 and α-Fe2O3, respectively. Beyond high activity, γ/α-500 maintained robust performance across a wide pH window (3-11), showed strong tolerance toward anion interference, and delivered stable reusability. Characterizations and theory calculations indicate that the homojunction-induced built-in electric field greatly facilitated charge separation, and enhanced PMS adsorption and reduced activation energy. This work not only demonstrates the design of a γ/α-phase Fe2O3 homojunction with an ultralow energy barrier for PMS activation but also offers a promising strategy for tailoring iron oxide-based catalysts toward efficient and sustainable remediation of emerging contaminants.

The exploitation of efficient and stable photothermal catalyst for the deep mineralization of volatile organic compounds (VOCs) is crucial and challenging. Herein, a photothermal catalyst with abundant oxygen defects was prepared for the first time via Cu-doped ZnMn2O4 hexagonal nanoplate. Experimental characterization results reveal that Cu doping enhances not only the ZnMn2O4 defect contents but also the light absorption and thermal conversion ability of ZnMn2O4. Compared to the undoped ZnMn2O4 (ZMO), the ZnMn2O4 with optimal Cu doping amount (ZMO-4Cu) exhibits excellent photothermal catalytic performance (94% toluene conversion and 87% toluene mineralization) and good resistance to low concentration SO2 under full-spectrum light irradiation. Experimental characterizations and theoretical calculations jointly demonstrated that the oxygen vacancies of ZMO-4Cu surface are more conducive to the adsorption of O2, effectively reduce the oxygen dissociation energy of ZMO-4Cu, thus generating abundant active oxygen species and improving the photothermal catalytic activity for toluene oxidation. In situ IR experiments disclosed that photothermal catalysis is more conducive to the toluene deep oxidation than thermal catalysis. This work provides new insights for the design of high efficiency photothermal catalysis for the deep oxidation of VOCs.

Photocatalytic technology for the NO reduction has tremendous potential at ambient conditions compared to conventional NO abatement technologies. Modulation of delocalization and localization of photogenerated electrons is crucial in photocatalysis, yet remains a grand challenge. Here we report a strategy involving PdCu single-atom alloys (SAAs) on HxMoO3−y that drives photocatalytic NO reduction toward NH3 with 100% selectivity, a high yield rate of 28.2 mmol h−1, and a total NH3 yield of 24.3 mmol within 120 h, which shows a prominent advantage in the area of photocatalytic NO reduction to NH3 at ambient conditions. Detailed experiments and characterizations combined with theoretical calculations demonstrate that (1) the paired Pd-Cu sites as highly active centers contribute local d-orbitals electrons to NO for NH3 synthesis and facilitate the formation of HNO*; (2) the sufficient delocalized electrons induced by plasmon resonances of HxMoO3−y can further replenish the depleted d-orbitals electrons in PdCu SAAs. Importantly, the well-retained performance of photocatalyst for NO removal in simulated flue gases demonstrates huge potential for its industrial application.

Simultaneous removal of refractory pollutants and heavy metal ions in wastewater is always a challenge. Herein, we developed a Fe-Mn-montmorillonite (MMT) Fenton-like catalyst for the simultaneous oxidation of methylene blue (MB) and reduction of chromium (Cr(VI)) in aqueous solution. The as-prepared Fe-Mn-MMT catalyst exhibited much higher catalytic activity than Fe-MMT and Mn-MMT catalysts, which can be ascribed to utilization of synergistic Fe(III)/Fe(II), Mn(IV)/Mn(II), and Cr(VI)/Cr(III) redox cycles, where Cr(VI) is not only detoxified to Cr(III) but also contributes to center dot OH generation, enhancing MB mineralization in the Fe-Mn-MMT/ H2O2 system. MB was almost completely mineralized, and Cr(VI) was converted to less toxic Cr(III) by the Fe-Mn-MMT/H2O2 system. Moreover, Fe-Mn-MMT showed excellent catalytic activity for MB decomposition at pH 3.14, 7.06 and 10.21. The catalyst still exhibited high catalytic activity even after five cycling runs. The degradation pathways of MB degradation in the Fe-Mn-MMT/H2O2 system were also discussed in detail. Finally, a possible mechanism for simultaneous removal of MB and Cr(VI) in the Fe-Mn-MMT/H2O2 system was proposed based on scavenger experiments, XPS, and EPR analyses. This study provides a novel Fenton-like catalyst for the simultaneous removal of refractory contaminants and heavy metal ions in combined wastewater.

Although hematite is a promising candidate for peroxymonosulfate (PMS) activation due to its low biotoxicity and cost-effectiveness, its application in the efficient degradation of organic pollutants is hindered by the limited availability of redox-active Fe sites. In this study, sulfur-decorated hematite nanoplates (SHNPs) were synthesized via a sulphuration strategy. The resulting SHNPs retained their hexagonal morphology while exhibiting increased surface cracks, thereby providing more active sites for tetracycline (TC) degradation. Among the synthesized catalysts, SHNPs-0.5 demonstrated the highest catalytic activity, achieving a degradation rate constant of 0.1162 min-1 under dark conditions-14.17 times higher than that of pristine hematite nanoplates (HNPs). Under visible light irradiation, the degradation rate further increased to 0.1466 min-1, with a final TC removal efficiency of 85.35 %. The enhanced degradation performance and accelerated kinetics of SHNPs were primarily attributed to the increased redox sites of Fe0, Fe(II) and S2-. Density functional theory (DFT) calculations revealed that sulfur modification enhanced charge transfer capability, facilitated PMS adsorption, and reduced the work function of the catalyst, all of which contributed to more efficient PMS activation and TC degradation. This work offers a viable approach for tuning the redox-active sites of transition metal-oxide catalysts for the removal of organic contaminants.