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A sustainable approach utilizing a low-temperature molten salt strategy is employed in this study to fabricate homogeneous and dense NiFe nitrate hydroxide needle-like arrays on a NiFe foam substrate. The electrode also achieves an ultra-low voltage of 1.77 V at 100 mA cm−2 and maintains stability for more than 120 h at a current density of 100 mA cm−2, showing excellent overall water splitting (OWS) performance and stability. Notably, the molten salt strategy enables the synthesis of electrodes at a reaction temperature as low as 125 °C. Additionally, the molten salt precursor is repeatable and renewable, thus preventing waste and presenting vast potential for application. [ABSTRACT FROM AUTHOR]

The crystalline phase effect of zirconia provides a viable approach to investigate the interfacial sites of Ag/ZrO2 catalysts in the hydrogenation of carbon–oxygen bonds. However, zirconia with different crystalline phases synthesised through general strategies faces the dilemma of ill-definition and huge structural differences, which present an insurmountable obstacle for the establishment of structure–activity relationships and the revelation of interfacial co-catalytic sites. This paper presents a novel synthetic strategy for the univariate modulation of zirconia crystalline phases. Compared with traditional strategies, the structure of zirconia synthesised by this strategy with different crystalline phases exhibits a high degree of similarity. Differently, the phase transition process endows monoclinic zirconia with a distinctive surface Zr3+–Ov site, which has been demonstrated to possess a robust adsorption capacity for carbon–oxygen bonds through in situ infrared spectroscopy and theoretical calculations. The coordination of surface Zr3+–Ov sites with silver sites capable of spilling hydrogen provides a novel interfacial co-catalytically active site-mediated reaction pathway for carbon–oxygen bond hydrogenation. The Ag/Zr–NH4+ catalyst with this novel interfacial site exhibited excellent catalytic performance in the activity evaluation, with ethyl glycolate yields reaching 95.8%. The interfacial co-catalysis offers a novel reaction pathway and is anticipated to be applicable to other carbon–oxygen bonded hydrogenation systems. [ABSTRACT FROM AUTHOR]

BixOyBrz, as a new class of promising layered materials for photocatalysis, have been extensively applied in CO2 reduction. Herein, a series of BixOyBrz with varied Br concentrations were synthesized to probe the contribution of the Br element to the Bi electronic structure, which dominates the conduction band (CB) of BixOyBrz materials. As the O atoms were replaced by the less-electronegative Br, the electronic environment around Bi3+ is altered, further resulting in a shift in the position of the ECB for BixOyBrz. Moreover, Br slabs are interleaved with the [BiO] layers, resulting in increased internal electric field (IEF) strength, which provides a strong driving force for the mobilization of photogenerated carriers. In conjunction with the optimal band structure and efficient carrier separation, BiOBr exhibits the highest catalytic activity with a CO yield of 24.8 μmol g−1. Meanwhile, in situ DRIFTS spectra illustrate the high-proportioned *CO2− active species on BiOBr, indicating the favorable conversion and activation of CO2. This study may provide insights into the role of the Br element in BixOyBrz materials and new opportunities for exploring efficient photocatalysts for CO2 photocatalysis. [ABSTRACT FROM AUTHOR]

This study introduces a novel approach for fabricating sub-micron dense GDC (Gd2O3 doped CeO2) barrier layers on YSZ (yttria-stabilized zirconia) electrolytes via in situ hydrothermal self-crystallization at an extremely low temperature of 180 °C. The dense GDC barrier layer self-crystallization in aqueous solution, was influenced by the orientation of the YSZ substrate. An anode-supported single cell with a GDC barrier layer ∼330 nm thick shows an Rohm of 0.075 Ω cm2 and PMax of 1.019 W cm−2 at 750 °C, which is a great improvement over single cell with a screen-printed GDC barrier layer (Rohm of 0.15 Ω cm2 and PMax of 0.661 W cm−2) and shows enhanced durability over 800 h. This enhanced performance is primarily due to shortend oxygen ions transport pathways, and an optimized electrolyte/cathode interface from effective interface sintering. This in situ hydrothermal self-crystallization method emerges as a promising and applicable technique for the preparation of a thin-film GDC barrier layer. [ABSTRACT FROM AUTHOR]

To overcome the weak adsorption and difficult activation of N2 on catalysts in the photocatalytic nitrogen reduction reaction (NRR), we put forward that the introduction of molecular sieve 13X may realize the enrichment and activation of N2. 13X and the photoactive substrate BiOBr were assembled electrostatically to construct composite catalysts. In the presence of 13X, they are rich in nitrogen adsorption and activation sites, and the highest ammonia yield can reach 360.5 μmol h−1 gcat−1. It is surprising to find that 13X is able to optimize the photoelectric properties. This work extends the function of molecular sieves in the NRR and offers guidance to design catalysts with high photocatalytic activity. [ABSTRACT FROM AUTHOR]

Suffering from inefficient carrier migration and the lack of active sites, the effective photocatalytic removal of low-concentration NO is still a formidable challenge. In this work, a NiAl-LDH/Bi4Ti3O12 Z-scheme heterojunction photocatalyst was prepared successfully through a facile two-step hydrothermal procedure. In this, the Fermi-level difference at the interface of Bi4Ti3O12 and NiAl-LDH results in the formation of a strong built-in electric field (BIEF). The strong BIEF enables the formation of a Z-scheme heterojunction, offering a novel charge transfer pathway that promotes the efficient migration of photogenerated electrons and holes while retaining their strong redox capability. Additionally, the unique NiAlLDH-modified sheet-like stacked nano-flower structure has a large specific surface area, which is beneficial for semiconductor absorption of sufficient photons to increase the concentration of charge carriers, and providing more reaction sites for the adsorption and activation of oxygen, thereby generating more reactive oxygen species. As a result, the optimized NiAl-LDH/Bi4Ti3O12 catalyst exhibits enhanced photocatalytic NO removal efficiency (75.51%), which significantly surpasses that of pristine Bi4Ti3O12 (62.35%) and NiAl-LDH (5.12%). The findings of this research offer insights into the rational development of Bi4Ti3O12-based heterostructure photocatalysts for air purification. [ABSTRACT FROM AUTHOR]

TiO2/BiOCl heterojunction photocatalysts with different molar ratios (Ti : Bi) were synthesized by a simple solvothermal method. Various spectroscopic techniques including X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), nitrogen adsorption–desorption, X-ray photoelectron spectroscopy (XPS), photoluminescence (PL) and UV-Vis diffuse reflectance spectroscopy (UV-vis DRS) were used to characterize the prepared photocatalysts. The photocatalytic activity of the catalysts was investigated by removing low concentrations of nitrogen oxides. The characterization results show that the TiO2/BiOCl composite photocatalyst exhibits superior visible light response performance than pure BiOCl and TiO2. The optimized TiO2/BiOCl heterojunction with a Ti : Bi molar ratio of 4 : 1 has the best photocatalytic performance. The removal rate of nitrogen oxides of the composite photocatalyst can reach 75%, which is 2.34 times higher than that of pure BiOCl. The observed photocatalytic degradation activity of nitrogen oxides outperforms current state-of-the-art functional photocatalysts. The TiO2/BiOCl composite photocatalyst has a larger specific surface area, stronger visible light absorption and higher charge separation efficiency compared to other control samples, which contribute to the enhanced photocatalytic activity. The experimental results indicate that the combination of TiO2 with BiOCl is a promising technique to design visible light-responsive photocatalysts. [ABSTRACT FROM AUTHOR]

Simultaneously achieving photoelectrochemical (PEC) water oxidation and degradation of organic pollutants coupled with H2 generation for bismuth vanadate (BiVO4) is highly desirable, while it is still hampered by low charge transport ability along with poor chemical durability. Herein, we have developed a NiFeOx co-catalyst decorated N-incorporated BiVO4 photoanode (N-BiVO4/NiFeOx), which not only can facilitate the charge transport efficiency but also efficiently suppresses the photo-corrosion. More specifically, the Fe sites trap photo-generated holes for promoting PEC processes and the Ni sites provide electrons to V sites for inhibiting V5+ dissolution of BiVO4. As a result, the large size N-BiVO4/NiFeOx photoanode with outstanding chemical stability exhibits efficient water oxidation and tetracycline hydrochloride (TCH) degradation coupled with H2 production performance. This work offers a promising avenue to design a high-performance photoanode and a new insight into antibiotic wastewater treatment. [ABSTRACT FROM AUTHOR]

Herein, by decorating NH2-MIL-125 (NM) with NiTiLDH (NTL), NMxNTLy is designed for the CO2 photoreduction reaction in only water media. The optimal NM3NTL1 presents electronic yields of 65.74 μmol g−1 h−1 with a CO selectivity of 96.2%. Supported by in situ irradiated X-ray photoelectron spectroscopy (ISIXPS) and Kelvin probe force microscopy (KPFM), the designed NMxNTLy forms the S-scheme electron transfer mode with an interfacial electric field from NTL to NM, facilitating the migration of e−/h+ pairs. NTL serves as an electron acceptor responsible for anchoring CO2, while NM is rich in holes for H2O oxidization, driven by coulombic forces under irradiation. Revealed by in situ DRIFTS, CO production follows the ˙CO2− and *COOH mechanisms. Significantly, we observed the reoxidation of CO from isotope labeling experiments, which could be inhibited on a S-scheme heterojunction with a spatially separated oxidation/reduction reaction. TPD coupled mass spectrometry (TPD-MS) suggests that the produced O2 might not completely desorb, which should explain for O2 readings below the theoretical values. This study provides new heterojunction photocatalyst designs and insights into the enhancement mechanism of the photocatalytic response. [ABSTRACT FROM AUTHOR]

The rational design of heterostructures, including the synthesis of candidate materials and the construction of structures, is particularly important for the activities of electrocatalysts. Herein, a unique heterostructure of ultrathin NiCo-LDH wrapped CuNiCo trimetallic spinel sulfides was constructed via facile hydrothermal and electrodeposition processes. Due to the ultrathin NiCo-LDH layer, the change in the local electronic structure resulting from the interaction of two components can be effectively transferred to the surface of electrocatalysts, which was verified by XPS tests. The heterostructure exhibits excellent activity and stability as efficient bifunctional electrocatalysts for overall water splitting. The corresponding overpotentials are 270 mV at 50 mA cm−2 for the oxygen evolution reaction (OER), and 93 mV at 10 mA cm−2 for the hydrogen evolution reaction (HER) in 1.0 M KOH, respectively. It is noteworthy that the OER activity exceeds that of RuO2. Meanwhile, the heterostructure presents excellent stability for more than 40 hours. The outstanding performance is attributed to the surface electronic structure of NiCo-LDH optimized by highly conductive and stable CuNiCo trimetallic spinel sulfides. The results confirm that it is an effective strategy to tune the catalytic performance by constructing a heterostructure with an ultrathin surface layer. [ABSTRACT FROM AUTHOR]

NiFe-based catalysts have attracted great attention due to their high activity in alkaline water oxidation. However, potential metal dissolution, in particular Fe, causes gradual deactivation during oxygen evolution reaction (OER). In this work, a monolithic catalyst of FeS2–Ni3S2 heterostructures and FeNi3 nanoparticles embedded within porous S, N co-doped carbon nanofibers was synthesized via in situ electrospinning. Such an integrated catalyst exhibits excellent OER activity with an overpotential of 270 mV to gain 10 mA cm−2. Under high-potential operations, the surficial reconstructed FeOOH and Ni(OH)2 active phases were detected by in situ Raman spectroscopy. The high Fe content maintains the low oxidation state of Ni at Ni2+, and conversely Ni has a positive effect on the intrinsic activity of the Fe site. The covalent interaction between Ni(OH)2 and the carbon encapsulation structure enhances the stability of FeOOH species. FeOOH and Ni(OH)2 synergistically catalyze the OER process assisted by conductive FeNi3 and S, N co-doped carbon. Such ingredients and monolithic structure not only alleviate Fe leaching, but also establish self-supportive ability to allow the anode reaction using a direct electrode without any additional substrates, which is conducive to adequate electrolyte infiltration and rapid O2 liberation. Taking advantage of the above-described pleiotropic properties, this monolithic catalyst realizes an appreciable stability of 50 h for successive O2 generation without any damage to the electrode structure. [ABSTRACT FROM AUTHOR]

The surface properties of the catalyst have an important influence on the process of heterogeneous reactions. We modified g-C3N4 with dicarboxylic acids with different hydrophobicity. Through experiments, we found that the NH3 yields of modified carbon nitrides can reach 267.89 μmol h−1 g−1 when only dissolved nitrogen is involved. But if both dissolved nitrogen and gaseous nitrogen are present in the reaction, the NH3 yield can reach as high as 751.83 μmol h−1 g−1, demonstrating that the participation of dissolved nitrogen alone is not enough and gaseous nitrogen indeed promotes the reaction of photocatalytic nitrogen fixation. Meanwhile, the nitrogen fixation performance of the catalyst is positively correlated with its hydrophobicity, indicating that a reasonable adjustment of the catalysts' hydrophobicity can give them a certain wettability to activate water, while also providing a hydrophobic surface for insoluble gas-phase nitrogen adsorption. This provides new ideas and directions for the design of future heterogeneous reaction catalysts. [ABSTRACT FROM AUTHOR]

A simple Pd/Cu-catalyzed borylation of allenylic carbonates with B2Pin2 was developed using a cheap P(OEt)3 ligand. Under mild neutral conditions, 2-boryl 1,3-butadienes were obtained selectively in moderate to high yields. Furthermore, the use of different diboron reagents was also feasible in the reaction. [ABSTRACT FROM AUTHOR]

A green and gram-scale strategy has been developed for the synthesis of Fe single atom/N,S-doped carbon catalyst (Fe20-SA@NSC) via the pyrolysis of polyaniline (PAN)-modified Fe,S-doped ZIFs, in which the synthesis of ZIFs can be accomplished in water at room temperature. The as-prepared catalyst exhibits superior activity in the N-alkylation of amines with alcohols via a borrowing strategy under solvent-free conditions (TOF up to 13.9 h−1). Based on the HAADF-STEM and XAFS results, Fe in this material is dispersed as the single-atom Fe1–N4S1 site. According to the experimental and theoretical calculation results, the Fe1–N4S1 site displays a better borrowing hydrogen ability than other Fe sites owing to its higher electron density. In addition, this catalyst has excellent stability and recyclability, and no obvious loss in activity is observed after 7 runs. [ABSTRACT FROM AUTHOR]

The 1T-MoS2/NiCo2S4 composite in situ grown on carbon cloth (CC) was successfully prepared by a two-step hydrothermal method as an efficient electrode for the hydrogen evolution reaction. The morphology and composition characterization show that the composite has a flower-like structure with a large number of edges and surfaces exposed, and the content of the 1T phase in MoS2 is 63%. 1T-MoS2/NiCo2S4/CC exhibits an overpotential of 107 mV at 10 mA cm−2, and a Tafel slope of 66.4 mV dec−1 in an alkaline electrolyte. After continuous electrolysis for 24 h at an overpotential of 170 mV, 86% of the original current density was retained in an chronoamperometry measurement. The outstanding catalytic performance of the composite is ascribed to its unique structure, high 1T-MoS2 content and the synergistic catalysis between 1T-MoS2 and NiCo2S4. This work provides a facile and effective strategy for fabricating the 1T-MoS2/NiCo2S4/CC composite and demonstrates that the composite is expected to be a competitive non-noble HER catalyst. [ABSTRACT FROM AUTHOR]

Direct conversion of greenhouse gas carbon dioxide (CO2) into lower olefins (ethylene, propylene and butene) provides an appealing approach to tackle CO2 emission challenges. Admixed catalysts composed of metal/metal oxides and SAPO-34 have been widely used for catalytic CO2 hydrogenation to lower olefins. However, interactions between metal/metal oxides and SAPO-34 remain obscure. Here, a novel family of admixed catalysts composed of Fe–Cu–K and SAPO-34 (Fe–Cu–K/SAPO) is developed for efficient catalytic CO2 hydrogenation to lower olefins, which can achieve 49.7% CO2 conversion and 62.9% selectivity of lower olefins, with CO selectivity <10%, over the optimal Fe0.45Cu0.45K0.10/SAPO-34 (with 1/1 mass ratio) catalyst. This exceptional performance is attributed to the change of structures, reducible properties and mass transfer resulting from strong interactions between metal/metal oxides and zeolites. First, SAPO-34 promotes the exposure of the active Cu–Fe (100) plane via disrupting the oriented growth process of Fe–Cu–K. Second, SAPO-34 boosts the reducible properties of Fe–Cu–K/SAPO-34, promoting CO2 adsorption and dissociation and thus resulting in the formation of -Fe3C active sites for hydrocarbon formation. Finally, the main mass transfer method of long-chain hydrocarbons/methanol from Fe–Cu–K to SAPO-34 is gas diffusion, and the dispersion of Fe–Cu–K over SAPO-34 accelerates such gas diffusion. This study provides a potential novel pathway to solve the challenge of efficiently converting CO2 into lower olefins and clarifies the effect of strong interactions between metal/metal oxides and zeolites on activities. [ABSTRACT FROM AUTHOR]

Although coupling highly pseudocapacitive species with flexible carbon substrates to fabricate hybrid electrodes holds promise for high-performance flexible supercapacitors, the structural collapse and performance degradation under repeated mechanical deformation remain a bottleneck to be tackled owing to the weak binding force between carbon and electroactive materials. Herein, well-controlled three-dimensional (3D) NS@NCCH tree-like core–shell microarrays grown on flexible and conductive Ni-plated carbon cloth (NPCC) are fabricated, with NiSe (NS) nanorods as the core and NiCo(CO3)(OH)2 (NCCH) nanosheets as the shell. The dense NS nanorod core in situ grown on NPCC, as a highly conductive and robust support, promotes electron transport as well as hindering the agglomeration of NCCH nanosheets. The NCCH nanosheet shell with a high specific surface area provides a bridge to combine the fast diffusion of electrolyte ions and ionic accessibility to the overall electrode surface. The synergistic contributions from the NPCC substrate and the core–shell NS@NCCH microarrays together with the natural gift of a 3D tree-like architecture enable the NS@NCCH/NPCC electrode to exhibit a high capacity of 6.89 F cm−2 (1642 F g−1, 228 mA h g−1) at 4 mA cm−2 and good rate performance. Furthermore, an assembled flexible all-solid-state asymmetric supercapacitor (FASSAS) based on the NS@NCCH/NPCC electrode retains an energy density of 53.8 W h kg−1 at a high power density of 15 kW kg−1 and exhibits excellent cycling stability with 91.5% capacitance retention after 5000 cycles. Especially, bending or twisting the FASSAS device to 180° causes negligible electrochemical property attenuation. [ABSTRACT FROM AUTHOR]

Spinel trimetallic sulfide M0.5Ni0.5Co2S4 (M = Cu and Mn) nanostructures are designed and synthesized for the first time via a facile one-pot solvothermal strategy and used as efficient counter electrodes (CEs) for quantum dot sensitized solar cells (QDSSCs). Electrochemical tests show that the interface charge transfer resistance (Rct) of Cu0.5Ni0.5Co2S4 is only 0.79 Ω, which is less than half of the Rct of NiCo2S4 (2.04 Ω). The best power conversion efficiency of QDSSCs assembled with the TiO2/CdS/CdSe/ZnS photoanode and Ti-mesh substrate Cu0.5Ni0.5Co2S4 CE reaches 5.20%. The superior electrocatalytic activity toward Sn2− reduction is attributed to the synergy effects of multiple transition metal heteroatoms, and the outstanding stability may stem from the distorted structures of spinel trimetallic sulfides. This work exhibits the potential of spinel trimetallic sulfides to be competitive CE material candidates for efficient QDSSCs. [ABSTRACT FROM AUTHOR]

It is crucial to determine the role and function of the mesopores in porous zeolite catalysis for NH3-SCR. Herein, a pore-controllable hierarchical Cu-SSZ-13 was assembled using a dual-template combining N,N,N-trimethyl-1-adamantammonium hydroxide (TMAdaOH) as the structure-directing agent with C16H33-[N+-methylpiperidine] (C16MP) as the mesoporogen. The introduction of C16MP drives the transition of the morphology of SSZ-13 from layered stacking to blocky stacking based on the arrangement of organic and inorganic species in the crystallization gel. Meanwhile, two different dimensions of mesopores are created by controlling the concentration of C16MP. During the induction and early crystallization stage, amorphous porous material dissolves and recrystallizes into CHA nuclei, followed by the conversion of partial mesopores to micropores. With increasing C16MP, the amount of 4Si species in the hierarchical Cu-SSZ-13 increased while the Si/Al ratio was unchanged, suggesting that the aluminum distribution may be regulated by mesoporogen. The interaction between micropores and mesopores improves the adsorption of NO and NH3. Above 400 °C, the presence of mesopores reduced the catalyst activity from 16% to 8% compared with micro-SSZ-13 and also maintained a high temperature activity. [ABSTRACT FROM AUTHOR]

Biomass-derived porous carbon is widely used in supercapacitors, carbon dioxide capture and lithium–sulfur batteries owing to its advantages such as wide sources, low cost and good stability. However, it is rarely used in quantum dot-sensitized solar cells (QDSCs). Here, glucose-derived porous carbon was obtained by hydrothermal carbonization followed with high-temperature KOH activation, and employed as an efficient counter electrode (CE) for QDSCs. The CV, EIS and Tafel-polarization analysis showed that porous carbon exhibits excellent catalytic activity for reduction of Sn2−. The CE based on porous carbon activated at 900 °C (C900) presents best performance with interface charge transfer resistance (Rct) of 2.4 Ω cm2 due to the synergy between high graphitization degree and large specific surface area. The power conversion efficiency (PCE) of the QDSCs assembled with a CdS/CdSe sensitized TiO2 photoanode and the C900 CE is up to 5.61% under one sun illumination. The excellent catalytic activity of C900 is attributed to its large specific surface area and porous structure and high degree graphitization. This suggests that glucose-derived porous carbon can become a potential low-cost and efficient CE material for QDSCs. [ABSTRACT FROM AUTHOR]

A series of Zr-porphyrin metal–organic framework (Zr-PMOF)/ultrathin g-C3N4 (UCN) (ZPUCN) heterostructure photocatalysts, as stable and efficient catalysts for the photoreduction of CO2, have been fabricated via a facile in situ hydrothermal self-assembly method. An interfacial interaction is formed due to hollow Zr-PMOF nanotubes being surrounded by 3D ultrathin g-C3N4 (UCN) and benefiting from the ultrathin and conjugated π-structure of UCN, the unsaturated metal atoms and organic ligands of Zr-PMOFs can covalently link to organic g-C3N4. The interaction provides a platform for UCN as a conductor to transfer e− or as a donor to transfer e− to Zr–O cluster active sites to catalyze CO2, substantially achieving the spatial separation of charge carriers and suppressing the photogenerated electron–hole (e−–h+) pair recombination rate. Benefitting from the cooperative effects of the well-designed nanostructure and chemical grafting, in the absence of triethanolamine, cocatalysts and photosensitizers, the optimized ZPUCN hybrid not only exhibits a better CO evolution yield (5.05 μmol g−1 h−1), which is 2.2 times and 3.2 times higher than those of pure Zr-PMOFs and UCN, respectively, but also displays excellent stability after 96 h photocatalysis. Information about the mechanism is also elucidated from selected characterizations. [ABSTRACT FROM AUTHOR]

Adjusting the position of active components is critical to enhancing the activity of CHA structured small-pore zeolites for NO selective catalytic reduction. We herein synthesized a novel low-cost multi-metal Cu-Ce-La-SSZ-13 catalyst via a simple one-pot method and revealed the relationship between the position of active species and catalytic activity. The introduction of Ce4+ ions and La3+ ions can effectively regulate the Cu2+ cations to migrate from eight-membered rings to more active six-membered rings, which endows Cu-Ce-La-SSZ-13 with excellent low-temperature SCR activity. [ABSTRACT FROM AUTHOR]

In this study, to overcome the low charge transportation efficiency and poor visible light absorption ability, and achieve highly efficient photocatalytic applications, carbon nitride nanosheets with oxygen and carbon co-doping were successfully designed and fabricated. The resultant carbon nitride nanosheets exhibited efficient photocatalytic H2 evolution and CO2 reduction performance, highlighting the efficacy of such a strategy. The highest H2 evolution rate could reach 698.43 μmol g−1 h−1, higher than that for graphitic carbon nitride (GCN). For CO2 reduction, the photocatalytic system shows a high CO selectivity, and MG3.0 achieves the largest CO generation amount of 55.2 μmol g−1. This enhanced photocatalytic reduction performance could be attributed to oxygen and carbon co-doping, which achieves fast electron extraction and transfer, and improved visible light absorption ability. It should be noted that the excessive addition of glucose in the synthesis process could enhance conductivity and promote visible light absorption of carbon nitride, but suppress the H2 evolution and CO2 reduction ability. Simultaneously, the photocatalytic reduction mechanism is discussed. This work confirms that a carbon nitride semiconductor with oxygen and carbon co-doping could be easily prepared by this strategy, achieving efficient photocatalytic applications. [ABSTRACT FROM AUTHOR]

A single gold nanopore with high surface enhanced Raman spectroscopy (SERS) activity is fabricated on the tip of a glass nanopipette. Polystyrene (PS) nanospheres can be recognized from the SERS spectrum while passing through the single nanopore. [ABSTRACT FROM AUTHOR]

Multifunctional electrocatalysts with high catalytic activity and durability are needed for environmentally clean energy technologies such as water-splitting devices and metal–air batteries. Herein, we investigate a new catalyst, P-3G, consisting of a cation-ordered perovskite (PrBa0.5Sr0.5)0.95Co1.5Fe0.5O5+δ (PBSCF) and 3D porous N-doped graphene (3DNG). This new type of composite electrocatalyst simultaneously exhibited outstanding multifunctional catalytic activities and excellent stabilities for the oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and hydrogen evolution reaction (HER). A possible mechanism for the synergistic effects between perovskite oxides and 3DNG on ORR, OER and HER was firstly proposed by DFT calculations. The electrocatalytic activity of P-3G appeared to have great potential for a rechargeable Zn–air battery system. The operating voltage differences between the charge and discharge (Δη) of P-3G and Pt/C–IrO2 after 110 cycles were 0.63 V and 0.87 V, respectively, indicating the substantial durability of P-3G. Moreover, a water-splitting device using P-3G efficiently produced H2 and O2 gases at rates of 0.859 μL s−1 and 0.417 μL s−1, respectively. This study highlights extended applications of coupled perovskite oxides/carbon materials as versatile electrocatalysts for ORR, OER, and HER and unveils the cause of synergistic interactions between oxide and carbon by DFT calculation. [ABSTRACT FROM AUTHOR]

Understanding the ionic transport behaviour as well as temperature change caused by the Joule heating effect is important for the application of plasmonic nanopores. To explore the basic properties of ionic transport through nanopores, we assemble gold nanoparticles on the tip of a glass nanopipette to form a hydrophilic gold porous structure (hydro-GPS) that exhibits high Raman activity. [ABSTRACT FROM AUTHOR]

In this paper, black TiO2 without adding active components was developed for NH3-SCR-DeNOx. The catalytic activity tests showed that the NO removal efficiency of black TiO2 was always greater than 90% at 330–390 °C, which almost reached that of the commercial NH3-SCR-DeNOx catalyst. XRD, UV-vis, TG, EPR, XPS, H2-TPR, DFT and NH3-TPD analyses were carried out to study the structure–effectiveness relationship. We found that a large number of oxygen vacancies were formed over the black TiO2 surface. It was not only promoted the adsorption of NH3via direct (oxygen vacancies as Lewis acid sites for NH3 adsorption) and indirect (oxygen vacancies promote the formation of surface hydroxyl groups, which are Brønsted acid sites for NH3 adsorption) forms, but also improved the redox properties by promoting the reduction of Ti4+ to Ti3+. These changes lead to the superior catalytic activity of black TiO2 for NH3-SCR-DeNOx. Additionally, an in situ DRIFT study demonstrated that the NH3-SCR-DeNOx reaction over black TiO2 occurred via the Eley–Rideal (E–R) mechanism. Finally, the catalytic stability and resistance to H2O and SO2 of the black TiO2 catalyst were studied, and it showed good performances. This study offered new and important insights into the understanding of the role of oxygen vacancies in determining the physical and chemical properties of catalysts. [ABSTRACT FROM AUTHOR]

A novel 3D BiFeWOx/Bi2WO6 (BFW/BWO) composite has been synthesized via a facile one-pot hydrothermal process. A tight chemically bonded interface between the BFW and BWO could be constructed by this simple and environmentally benign method. The composite structures and chemical properties were investigated by XRD, FE-SEM, HR-TEM and EDS. The photocatalytic performances of the as-synthesized materials were assessed by photocatalytic oxidation (PCO) of NO under visible light illumination. The optimum BFW/BWO-1 composite exhibited 87% PCO efficiency, which was higher than that of the single phase BWO and BFW. The enhancement of the photocatalytic activity of the BFW/BWO-1 composite was ascribed to the effective separation and reduced recombination rate of the photoinduced charge carriers, evinced by transient photocurrent, EIS and PL measurements. The radical trapping experiment and DMPO spin-trapping ESR measurement revealed that H+ and ṖOH were the important active species. The tests for stability and recyclability revealed that the BFW/BWO-1 composite could be a desired photocatalyst for the oxidation of NO in the ecosystem. The kinetics and possible mechanism for the PCO of NO on the BFW/BWO-1 composites were discussed. [ABSTRACT FROM AUTHOR]

The development of the economy benefits from fossil fuels, but their consumption inevitably results in environmental pollution. For example, nitric oxide (NO) removal from coal-fired flue gas is a significant aspect of atmospheric pollution control. Based on its unique advantages to resolve atmospheric pollution, photocatalytic oxidation (PCO) is regarded as an effective technique to remove NO. Herein, we have first fabricated Z-scheme CaIn2S4/Ag3PO4 nanocomposites and studied their performance in the PCO of NO (400 ppm) with the assistance of H2O2. The results indicate that the CaIn2S4/Ag3PO4 nanocomposites exhibit superior photocatalytic performance, and the PCO efficiency of NO can reach 83.61%. The excellent photocatalytic ability belongs to the low recombination rate of the photoinduced electron–hole pairs. The production and participation of more active species is another critical factor due to the injected H2O2. FTIR and ion chromatography results reveal that NO3− is the final product. Furthermore, the fluorescence spectra combined with the electron spin resonance and the trapping experiment suggest that ṖOH and ṖO2− might play a predominant role in NO removal. [ABSTRACT FROM AUTHOR]

Polyaniline (PANI)-decorated Bi2MoO6 nanosheets (BMO/PANI) were prepared by a facile solvothermal method. Different characterization techniques, including X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, diffuse reflectance ultraviolet-visible spectroscopy, photoluminescence spectroscopy, electrochemical impedance spectroscopy, photocurrent spectroscopy, and nanosecond time-resolved emission studies, have been employed to investigate the structure, optical and electrical properties of the BMO/PANI composites. The wide absorption of the samples in the visible light region makes them suitable for nonlinear transmission and photocatalytic activity studies. The associated photocatalytic activity and optical nonlinearities for the BMO/PANI composites are shown to be dependent on the PANI loadings. The rational mechanisms responsible for deteriorating pollutants and improving optical nonlinearities were also proposed, which could be mainly attributed to the efficient interfacial charge transfer and the interfacial electronic interactions between PANI and Bi2MoO6. The photoluminescence spectroscopy, electrochemical impedance spectroscopy, and photocurrent spectroscopy studies confirmed that the interface charge separation efficiency was greatly improved by coupling Bi2MoO6 with PANI. The tuning of photocatalysis and nonlinear optical behaviors with variation in the content of PANI provides an easy way to attain tunable properties, which are exceedingly required in optoelectronics applications. [ABSTRACT FROM AUTHOR]

Two new high-energy metal–organic frameworks (HE-MOFs), {Ag2(DNMAF)(H2O)2}n (1) and {Ag2(DNMAF)}n (2) were prepared using potassium 4,4′-bis(dinitromethyl)-3,3′-azofurazanate (K2DNMAF) in a self-assembly strategy. Compound 1 exhibits a 3D HE-MOF structure with coordinated water molecules. Compound 2 exhibits compact solvent-free 3D HE-MOFs. Both compounds show good thermostability (decomposition temperature (Td) of 211 and 218 °C) and superior detonation velocities (D) of 9673 m s−1 and 10 242 m s−1, detonation pressures (P) of 50.01 GPa and 58.30 GPa, and heat of detonation (Q) of 1.95 kcal g−1 and 2.19 kcal g−1, respectively, which are even higher than those of RDX and HMX. [ABSTRACT FROM AUTHOR]

A surfactant-free solvothermal method was developed for the controlled synthesis of diverse 3D ms-BiVO4 superstructures, including a flower, a double-layer half-open flower and a hollow tube with square cross-sections, via facilely adjusting the pH values with the aid of NH3·H2O. The effects of the morphologies of the prepared 3D ms-BiVO4 superstructure on the photocatalytic oxidation of NO were investigated, indicating that the enhanced photoactivity was not related to the surface area, but associated with the unique morphology, surface structure and good crystallinity. Moreover, the flower-like ms-BiVO4 photocatalyst with a more (040) reactive crystal plane exhibited higher photoactivity than those of other samples. The unique morphology helped with flushing the oxidation products accumulated on the surface of photocatalysts in the H2O2 system, and further improved the photoactivity. A trapping experiment was also conducted to examine the effects of the active species involved in the PCO of NO intuitively. [ABSTRACT FROM AUTHOR]

The performances of Cr/Ti-PILC catalysts, which were prepared by the pre-modification method, are studied for the selective catalytic oxidation of NO. The aim of this paper is to elucidate the detailed relationship between physical nanoparticle structure and chemical properties. The maximum NO conversion over the Cr-HP(3)/TP catalyst reached 71.4% at 280 °C. The catalysts were characterized by powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), temperature-programmed reduction of H2 (H2-TPR), temperature-programmed desorption (TPD) and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) techniques. The characterization results demonstrated that the enhanced catalytic activity was ascribed to several beneficial effects, which were caused by the pre-modification such as the inhibition of crystallite size, improvement of Cr species dispersion and increase of the amount of active sites. XPS and FTIR experiments indicated that two Cr(vi) species, oxidized state CrO3 and chromate species with the anionic form, were generated via pre-modification, which played different roles in the catalytic reaction. In addition, the TPR and TPD results suggest that the increased active sites (Cr(vi) species) were conducive for the preferential adsorption and activation of NO. Furthermore, DRIFTS results revealed that the intermediates, NO+ and nitrates, interacted quickly to generate gaseous NO2. [ABSTRACT FROM AUTHOR]