Abstract With the aggravation of environmental pollution issues, the development of high-efficiency absorbents to tackle CO 2 emissions from industrial flue gas has become a research focus. In this paper, high-purity commercial CaO was selected as the research object and modified via a high-temperature pretreatment method to improve its CO 2 capture performance and cyclic stability. Experiments were conducted to investigate the influence of different pretreatment durations on the CO 2 capture performance of calcium-based absorbents under the condition of 800 °C. Various characterization techniques were combined to reveal the intrinsic correlation between their microstructure and performance. The results show that high-temperature pretreatment can effectively enhance the CO 2 capture performance of calcium-based absorbents. The CaO-S2 sample calcined at 800 °C for 2 h exhibits the optimal comprehensive performance. Although its initial adsorption capacity is about 0.30 g/g, slightly lower than that of the CaO-S0.5 sample, it remains at approximately 0.30 g/g after 10 calcination-carbonation cycles. This stability is due to its self-activation effect and excellent sintering resistance, making it significantly superior to other samples.

In this study, a significant breakthrough was achieved in the field of photocatalytic mercury removal using an iodine-doped BiOBr (I-BiOBr) photocatalyst prepared via the solvothermal method. Iodine doping not only formed active sites but also promoted the formation of oxygen vacancies (OVs). The optimized BI-5 catalyst demonstrates exceptional performance, achieving a mercury removal efficiency of 93.1 % under visible light, representing a 5.58 times increase in removal rate compared to pure BiOBr. Density functional theory (DFT) confirmed that the introduction of iodine both adjusts the electronic structure and reduces the OV formation energy by 0.198 eV. The catalyst maintained stable performance during a long-term test of 3,1000 s, demonstrating practical durability suitable for industrial applications. This study provides a new approach for photo-catalytic removal of heavy metals from flue gas.

Formic acid (FA) is a liquid hydrogen carrier with high volumetric hydrogen capacity, excellent stability, and renewability. To promote the application of FA as a green hydrogen carrier, a low-cost, high-activity catalyst for formic acid dehydrogenation was developed in this work. Using 3-Hydroxytyramine hydrochloride as the carbon source, a hollow carbon sphere support was prepared via the self-polymerization template method, with reaction reagents precisely regulated. Pd nanoparticles featuring uniform charge distribution and excellent dispersion were loaded onto the carbon sphere surface, yielding a nitrogen-containing carbon sphere-supported Pd catalyst (Pd@DHK-1). Under the optimal conditions (5 wt% Pd loading, 323 K reaction temperature), Pd@DHK-1 exhibited 100% hydrogen selectivity and achieved a turnover frequency (TOF) of 15,327 h- 1 for formic acid dehydrogenation. Additionally, the catalyst demonstrated excellent stability, retaining a high TOF of 6568 h- 1 after 6 consecutive cycles. Pd@DHK-1 exhibits outstanding performance for two key reasons: the self-polymerization template method enables directional regulation of dopamine-derived carbon sphere morphology, and APTES modification introduces amino groups onto the support. These factors synergistically enhance the anchoring and dispersion of Pd nanoparticles, thereby significantly improving catalytic performance. This work provides a novel strategy for the development of high-efficiency catalysts and the optimization of reaction processes for formic acid dehydrogenation.

Background The development of highly efficient photocatalysts modified with rare earth elements for the removal of elemental mercury (Hg0) from industrial flue gas remains a key challenge in the field of environmental remediation. Methods Herein, we report a samarium-doped bismuth oxybromide (Sm-BiOBr) photocatalyst synthesized via a facile solvothermal method, which shows exceptional visible-light-driven photocatalytic activity for Hg0 oxidation. Comprehensive characterization techniques, including in situ XPS, TRPL, and EPR spectroscopy, revealed that Sm doping promotes charge separation in the photocatalyst, which enhances its photocatalytic performance under visible light. Significant Findings This unique valence-state equilibrium facilitates efficient electron transfer, as evidenced by a 3.69-fold enhancement in reaction kinetics compared to pure BiOBr. The optimized BS4 photocatalyst exhibits remarkable stability during prolonged testing, maintaining 80.9% Hg0 removal efficiency under simulated flue gas conditions containing SO2, NO, and HCl. Density functional theory (DFT) calculations confirmed that the narrowing trend of the band gap was consistent with the experiment, and the electronic properties were analyzed using the electronic state density (DOS). This work establishes a new paradigm for designing advanced photocatalysts through rare-earth engineering, offering a sustainable solution for heavy metal pollution control in complex industrial emissions.

The photocatalytic reduction of CO2 to C2 products with high selectivity under visible light remains a grand challenge primarily due to the high-energy barriers and kinetic complexities of C-C coupling. The current strategies primarily concentrate on augmenting the number of carriers to activate the multielectron transfer system, often overlooking the mechanism by which the coupling effect of catalyst surface energy influences intermediates. Herein, we report a strategy that synergizes vacancies and plasmonic Pt to steer the high energy of key intermediates for selective C2 production. The constructed catalyst achieves an exceptional ethylene yield of 86.81 μmol·g-1·h-1 with near-unity selectivity (∼100%), significantly outperforming most reported systems. Concurrently, experimental findings indicate that the elevation of the substrate electron orbitals is positively correlated with the coupling strength of the CO intermediate. This work not only showcases a high-performance photocatalytic approach for the reduction of CO2 to C2 but also deciphers the fundamental role of electron orbital energy levels in steering the selectivity of C2 products.

Elemental mercury in coal-fired flue gas is difficult to capture due to its volatility and poor solubility, posing a serious challenge for emission control. Herein, we report the construction of an S-scheme Bi2MoO6/g-C3N5 heterojunction via an in-situ synthesis method to address this issue. The optimized 45BMO-CN composite achieved an outstanding Hg0 removal efficiency of 91 %, significantly outperforming pure Bi2MoO6 and g-C3N5. Notably, the catalyst exhibited excellent stability, maintaining over 85 % mercury removal efficiency after approximately 40,000 s of continuous operation, demonstrating its durability and long-term effectiveness. Structural and surface analyses revealed that the heterojunction enlarged the specific surface area, introduced abundant oxygen vacancies, and facilitated intimate interfacial coupling. Electrochemical characterizations demonstrated accelerated charge separation and reduced transfer resistance, while density functional theory (DFT) calculations confirmed the formation of an internal electric field that drives directional electron transfer across the interface. The synergistic effects of g-C3N5 and Bi2MoO6 enable efficient utilization of photogenerated carriers, thereby enhancing both redox capacity and stability. This work not only establishes a clear structure-activity relationship for S-scheme heterojunctions but also provides important insights for designing highly efficient and stable photocatalysts for mercury removal.

Abstract Using 2-chloroterephthalic acid and zirconium salts as raw materials, a chlorine-functionalized metal-organic framework, ZIF-678@UiO-Cl, was synthesized via a hydrothermal/solvothermal method. The physicochemical properties of the material, including its crystal phase composition, morphological characteristics, and pore structure parameters, were characterized by SEM, TEM, XRD, XPS, and Hg-TPD. Combined with mercury removal performance tests, the adsorption behavior and mercury removal mechanism of the material were investigated, providing experimental support and mechanistic insight for further research and application of chlorine-functionalized MOFs in flue gas mercury removal.

The development of highly efficient and stable lead-free narrow-bandgap perovskite solar cells (PSCs) is crucial for overcoming the toxicity of lead-based materials and carrier transport bottlenecks. This simulation work explores the performance potential of the narrow-bandgap Ba3SbBr3 (0.976 eV) by establishing a theoretical design paradigm via SCAPS-1D, with a focus on band engineering and defect management. A "micro-offset spike" strategy is theoretically proposed and investigated through numerical simulation, which involves engineering valence band offset (VBO) of 0.01-0.05 eV in the CuO hole transport layer (HTL) to synergistically suppress interfacial recombination and enhance hole extraction. Coupled with parabolic conduction band offset (CBO) modulation in the ZnxCd1-xS electron transport layer (ETL) - achieving a theoretically optimal CBO of 0.23 eV at 30 % Zn - and the co-optimization of Ba3SbBr3 thickness (1100 nm), NA (acceptor doping density 1 x 1018 cm-3), and asymmetric regulation of interfacial defect layers (IDLs), a maximum power conversion efficiency (PCE) of 25.39 % is predicted under idealized conditions. The simulated device is predicted to exhibit an extended infrared response up to 1270 nm (covering 43 % of the solar irradiance) and maintain PCE above 20 % over a wide temperature range of 240-420 K. This work establishes a comprehensive simulation framework, aiming to inform and accelerate subsequent experimental development of Ba3SbBr3 solar cells.

With the growing concerns over global climate change and rising energy demands, environmental challenges linked to carbon dioxide (CO2) emissions have gained significant visibility. Converting CO2 into high-value fuels not only helps mitigate the greenhouse effect but also facilitates the reuse of carbon resources. Among available conversion approaches, photocatalytic CO2 reduction has drawn interest for relying on solar energy and operating through a green process. Bimetallic sulfide catalysts stand out in this context, offering distinct advantages including broad visible-light absorption, adjustable electronic properties, and plentiful surface-active sites. This review systematically surveys recent developments in bimetallic sulfide photocatalysts applied to CO2 reduction. It clarifies fundamental structure-property correlations in representative materials including ZnIn2S4, CuInS2, and CdIn2S4, illustrating how synergistic interactions between metal components direct their optoelectronic performance. This review scrutinizes the complex reaction mechanisms leading to products such as CO, CH4, and C2H5OH, with particular emphasis on the role of sulfur vacancies and surface configurations in activating inert CO2 molecules. Furthermore, it delineates methodologies for boosting photocatalytic efficiency, including structural and morphological control, defect engineering, constructing heterojunctions, and cocatalyst loading. This work concludes by identifying prevailing limitations and promising avenues within this dynamic research domain. Intended as a foundational guide, this review aims to serve as a foundational reference for the rational design of efficient and selective bimetallic sulfide catalysts toward solar-driven CO2 valorization.

Semiconductor photocatalytic reduction of CO2 is one of the possible ways to utilize CO2 resources in the future. In order to further improve the yield and selectivity of the reduction products, it is essential to regulate the active sites and the local energy of the catalyst. In this work, Pb-doped CuMoO4 nanocrystal was prepared for the highly selective photocatalytic reduction of CO2 to CO. The CO yield is increased by 6.45 times, reaching 4.65 mu mol g(-1) h(-1), and the CO selectivity is as high as 95%. The incorporation of Pb endows the catalyst with superior electron transfer properties and an optimized band structure. DFT calculations further reveal that the bimetallic sites formed by Pb and Cu significantly promote the adsorption and activation of CO2 on the catalyst surface. This work offers a reliable scheme for the preparation of high-performance catalysts and valuable insights into the mechanism of CO2 photocatalytic reduction.

In coal-fired power plants, mercury is released into the atmosphere along with flue gas during the combustion of coal, posing serious threats to both the environment and human health. In this work, a novel core-shell structured Zr/Br dual-doped metal-organic framework adsorbent UIO-type-Zr-Br was successfully synthesized using a multistep templating strategy with precise control of structural modulation. Through a combined strategy of ZIF67@ZIF-8 NPs nano-etching and Zr/Br doping, the optimal sample UIO-15 exhibited excellent mercury removal performance, achieving over 98.8% removal efficiency at 120 degrees C. The UIO-15 adsorbent also demonstrated strong resistance to coal combustion flue gas interference components such as SO2 (600 ppm) and NO (600 ppm), maintaining nearly 80% efficiency. Furthermore, long-term dynamic tests showed that UIO-15 retained approximately 95% efficiency after 10 h of continuous operation. The Zr4+ and centers maintained the oxidation state throughout the reaction, indicating the role as structural stabilizers rather than redox-active sites, while Br- participated in the oxidation of elemental mercury Hg0 to form stable HgBr2, which was subsequently immobilized within the MOF framework; Mercury removal was effected by dual-functional oxidationfixation centers formed via synergistic Zr4+-Br- interactions. These findings suggest that UIO-15 is a promising candidate for practical application in mercury removal systems for coal-fired power plants.

The exploration and development of non-precious metal cocatalysts that can replace precious metal cocatalysts are crucial for enhancing the performance of monomer photocatalysts and promoting the practical application of photocatalytic technology. In this study, a series of x% NiSe/ZIS6 composite photocatalysts based on pure Zn3In2S6 were prepared by a simple ultrasonic-assisted deposition method using non-precious metal NiSe as the cocatalyst. The crystal phase structure, microscopic morphology, surface chemical valence state, and successful preparation of the prepared samples were comprehensively studied by characterization methods. Compared with the monomer Zn3In2S6, all the x% NiSe/ZIS6 composites exhibited significantly improved photocatalytic hydrogen production performance. The amount of NiSe introduced significantly influences the photocatalytic hydrogen production performance. With a hydrogen production rate of 12.41 mmol g- 1 h- 1, the photocatalyst exhibits 7.48 times higher activity than the pure ZIS6. The reason for the improved photocatalytic hydrogen production can be attributed to the fact that the introduction of NiSe as a cocatalyst significantly enhanced the light absorption performance of the composite photocatalyst. In addition to promoting charge separation, it is also considered an active center for hydrogen evolution reactions, which may provide more active sites for the reaction. This research provides valuable reference for the design and construction of high-performance noble metal-free cocatalysts/semiconductor composite photocatalysts using metal selenides as cocatalysts.

The construction of S-scheme heterojunctions is widely recognized as one of the most powerful strategies in the field of photocatalysis for effectively separating photogenerated charge carriers while simultaneously maintaining strong oxidation and reduction capabilities. In this study, the ternary metal sulfide ZnCo2S4 was synthesized through a facile hydrothermal method, and a series of ZnCo2S4/Zn2In2S5 S-scheme heterojunction photocatalysts were subsequently prepared by ultrasonically depositing varying amounts of ZnCo2S4 onto Zn2In2S5. Experimental results demonstrate that the loading amount of ZnCo2S4 in the composite photocatalyst significantly influences the photocatalytic hydrogen production performance. Among them, the 10 % ZnCo2S4/ Zn2In2S5 composite photocatalyst exhibits the optimal hydrogen production performance, with a hydrogen evolution rate of 27.97 mmol center dot g-1 center dot h-1, approximately 8.23 times that of Zn2In2S5. The significant enhancement in photocatalytic activity of the ZnCo2S4/Zn2In2S5 composite photocatalyst can be attributed to the well-matched band structures and intimate contact between pure ZnCo2S4 and Zn2In2S5, which effectively constructs an Sscheme heterojunction. This heterojunction efficiently suppresses the recombination of photogenerated charge carriers and promotes their separation and transfer. This study provides an exemplary model for constructing Sscheme heterojunction photocatalysts with high photocatalytic hydrogen evolution performance.

The rational design of efficient electrocatalysts from earth-abundant materials is crucial for advancing watersplitting technologies. This study presents a breakthrough in transition metal selenides (TMSes) by employing a synergistic dual-atom doping strategy, where Ni/Co cations are incorporated and Se vacancies are engineered to significantly enhance electrocatalytic performance. The nanoflower-like Ni@Co/Se2 catalyst, synthesized via a one-step hydrothermal method, exhibits an exceptionally low oxygen evolution reaction (OER) overpotential of 230 mV at 10 mA cm-2, surpassing most reported TMSes. Mechanistic studies reveal that the dual-atom doping induces charge redistribution, while the Se vacancies optimize the adsorption of oxygen intermediates, collectively lowering the OER energy barrier. Density functional theory (DFT) calculations further confirm that the unique nanoflower structure facilitates electrolyte penetration, enhances electron transfer during redox processes, and optimizes the electronic structure, accounting for the enhanced electrochemical kinetics. This work provides fundamental insights into the structure-activity relationship of dual-atom doped TMSes, offering a new horizon for designing high-performance electrocatalysts for sustainable energy applications.

The preparation of micro- and nanocapsule phase change materials (NPCMs) always requires the help of emulsifiers, leading to additional cost, time and energy consumption. In this study, we prepared a polyethylene glycol (PEG)-based NPCM without using emulsifiers, showing a sustainable development of engineering. The amphiphilic prepolymer of the NPCM could self-emulsify in water forming nano micelles, which were subsequently chemically cross-linked by trimethylolpropane obtaining the NPCM. The chemical crosslinking structure endows the NPCM with a solid state even at 90 degrees C, addressing the leakage issue of PEG. Due to the introduction of hydroxyl-functionalized multi-walled carbon nanotubes (OH-MWCNTs), the NPCM has an enhanced thermal conductivity of 1.04 W m-1 K-1, which is much greater than those of PEG and the NPCM without the OHMWCNTs. The latent heat values of the NPCM in the heating and cooling processes are 74.4 and 72.3 J g-1, respectively, manifesting good thermal energy storage capability. Additionally, the NPCM also has good thermal stability and thermal reliability.

In order to cope with the continuous growth of global energy demand and extreme climate, and achieve the Sustainable Development Goals, countries are accelerating the green transformation of energy structure. Perovskite solar cells (PSCs) have become a research hotspot because of their low energy consumption and wide application prospects. BaZrS3-based perovskite has become a new alternative material due to its non-toxicity and high stability. In this paper, density functional theory (DFT) and solar cell capacitance simulator (SCAPS-1D) are used to investigate the performance of BaZrS3 based materials and solar cell devices. The band structure and optical properties of BaZrS3-based crystals are calculated and analyzed by using MS CASTEP module, and the simulation analysis of SCAPS-1D is further optimized. The innovative application of the absorption layer material as the hole transport layer further improves the power conversion efficiency while facilitating band matching. In addition, the performance of the device under different metalworking functions is also studied. In this work, Ni is selected as the metal back electrode, which further saves the cost, solves the problem of high cost of perovskite solar cells, reduces the process complexity, and further improves the PCE through simulation. The optimized PCE and fill factor (FF) reached 35.02 % and 90.2 %, respectively. In this paper, CASTEP module is used to analyze the internal mechanism of PCE by DFT calculation, and the high excitation PCE is obtained, and the PSCs have good stability. What is exciting is that this perovskite solar cell structure has good power conversion efficiency and stability at the extreme temperatures of solar cells. These results show that the material has a good practical application prospect in the photovoltaic field.

As the world shifts towards low-carbon development, the deployment of highly efficient catalysts for the oxygen evolution reaction (OER) and the oxygen reduction reaction (ORR) in energy conversion and catalytic systems is crucial for addressing the energy crisis. To explore the impact of transition metal doping in the fourth period and doping of different period and group metals on the performance of catalysts, the catalytic activity of M-COF-C4N (M = Ni, Mn, Fe, Co, Bi, Te, Ce) against ORR and OER was systematically studied based on the density functional theory(DFT) method. Using metal anchoring to the substrate, different metals adjust the binding strength of oxygenated intermediates by anchoring to the M-N2 site, affecting the catalytic activity. CoCOF-C4N and Ni-COF-C4N are with lower ORR and OER overpotential (eta ORR, eta OER) values, and it is lower than that of Pt (111). These two COF-based materials, Co-COF-C4N and Ni-COF-C4N, are highly efficient bifunctional catalysts, which can serve as effective catalysts with eta ORR values of 0.24 V and 0.35 V respectively, and eta OER values of 0.29 V and 0.34 V respectively, the efficient redox mechanism of such catalysts was elucidated. This study develops a valuable pathway for the discovery of more efficient and economical two-dimensional mesh materials as highly efficient electrocatalysts, and could effectively contribute to the global transition to green energy.

Construction of S-scheme heterojunctions is widely recognized as one of the high-efficiency strategy to promote the separation and migration efficiency of photogenerated carriers and maintain stronger oxidation and reduction capabilities. In this study, a series of novel ZnWO4/ZnS (ZWO/ZnS) composite photocatalysts were constructed by in situ loading ZWO on the surface of semiconductor ZnS through a simple hydrothermal method. Advanced characterization methods such as XRD, SEM, TEM, XPS, etc. have convincingly demonstrated the successful preparation of the ZWO/ZnS composites. The hydrogen production performance of all composites is much higher than that of pristine ZWO and ZnS. Among them, the photocatalytic hydrogen production performance of 8 % ZWO/ZnS is the best, with a hydrogen production rate as high as 15.46 mmol center dot g-1 center dot h-1, which is 6.36 and 3.74 times that of pure ZWO and ZnS, respectively. The dramatically improved photocatalytic activity primarily stems from the engineered S-scheme heterojunction, which effectively enhances the separation and transport dynamics of photogenerated charge carriers while simultaneously preserving robust redox potential. This research can provide a referential example for constructing S-scheme heterojunctions with highperformance hydrogen production performance by using inexpensive and easily prepared wide bandgap semiconductors.

Hg0 pollutants in the flue gas of coal-fired power plants pose a significant threat to the environment. Exploring the efficient removal of Hg0 using environmentally friendly photocatalytic technology is of great importance. Bi-based photocatalysts have become a research hotspot in the field of photocatalysis due to their tunable bandgap and excellent catalytic performance. The 2D/2D Bi2O2CO3/Bi2MoO6 Z-scheme heterojunction composite photocatalyst was constructed via in situ epitaxial growth of Bi2MoO6 nanosheets on Bi2O2CO3 through their highly similar [Bi2O2]2+ layered structures, achieving exceptional photocatalytic Hg0 oxidation efficiency in flue gas (with an efficiency of up to 92.21 %). The 2D/2D configuration provides an extensive contact area, making it an ideal optoelectronic platform for exploring heterojunction designs. The structure of the composite photocatalyst was characterized using XRD, SEM, TEM, BET, and AFM, confirming the successful construction of the 2D/2D heterojunction. The optimal sample, BOC-BMO-2, exhibited excellent photoelectrochemical performance and photocatalytic stability, attributed to the strong bonding between the [Bi2O2]2+ layers of Bi2O2CO3 and the [MoO4]2− layers of Bi2MoO6. Combined XPS, ESR, and DFT analyses elucidated the Z-scheme heterojunction's regulatory role in charge carrier dynamics, where the synergistic interplay between the intrinsic internal electric field (IEF) and engineered oxygen vacancies (Ov) significantly enhanced charge separation and directional migration. Leveraging the exceptional charge separation efficiency of the 2D/2D Bi2O2CO3/Bi2MoO6 photocatalyst, this work successfully identified the reaction mechanism and detailed pathway for Hg0 oxidation. The findings provide a groundbreaking strategy for constructing stable and efficient Z-scheme heterojunctions, with far-reaching applications in air purification and global mercury management.