Search

A new homojunction is developed by in situ decorating g-C3N4 (CN) nanosheets with a C–N compound broken by s-triazine units (BST). The BST fragments rapidly transfer photogenerated electrons from the CN conduction band to generate hydrogen.

SSZ-13 has been commercialized as a catalyst in diesel engines for the selectivity catalytic reduction of nitrogen oxides (NO

TiNb2O7 (TNO) as a promising candidate anode for lithium-ion batteries (LIBs) shows obvious advantages in terms of specific capacity and safety, but which undergoes the intrinsic poor electrical and ionic conductivity. Herein, we propose a simple synthesis strategy of mesoporous TNO via a polymeric surfactant-mediated evaporation-induced sol-gel method, using polyvinylpyrrolidone (PVP) with different molecular weights (average Mw: 10000/58000/1300000) as the regulating agent, which greatly affects the lithium storage performance of the as-prepared TNO. The optimized TNO (i.e., PVP of 58000) delivers a high reversible capacity of 303.1 mAh/g at 1 C, with a retention rate of 73.4% (222.5 mAh/g) after 300 cycles. Even at 5 C, a high reversible capacity of 185.6 mAh/g can be achieved, with a retention rate of 72.3% after 1000 cycles. The superior lithium storage behavior is attributed to the fine mesoporous framework consisting of interconnected TNO nanocrystallites with high specific surface area and high mesoporosity, which greatly increases the active sites, improves the Li+ diffusion kinetics and alleviates volume fluctuation induced by the repetitive Li+ insertion-extraction processes.

A new variety of CdS/NiO core-shell p-n heterojunction is synthesized by in-situ chemically depositing NiO shell on single-crystal CdS nanorods for the first time. With this method, the range of NiO shell thickness can be accurately controlled within a few nanometers. The optimized CdS/NiO sample (CSN0.5) with a NiO shell layer of 1.5 nm exhibits a highly efficient photocatalytic H2 evolution rate of 731.7 μmol/h (corresponding to 243.9 mmol/g/h) without using co-catalyst, which is among the highest value of all the CdS-based photocatalysts. The apparent quantum efficiency (AQE) of CSN0.5 at 365 nm wavelength reaches 28.19%. The remarkably enhanced photocatalytic performance can be attributed to a hydrogen spillover effect induced by ascorbic acid in CdS/NiO, which promotes the transmission of adsorbed H* from hydrogen-rich NiO (electron-poor region) to hydrogen-poor CdS (electron-rich region) where the adsorbed H* reacts in time with the photogenerated electron to produce H2, facilitating the H2 evolution reaction. This work provides a method to promote the photocatalytic H2 evolution reaction by using hydrogen spillover effect.

As a kind of white light emitting diode (w-LED) with many advantages, rare-earth-free vanadate phosphor has attracted more and more attention. The oxygen vacancies and other surface defects in vanadate oxide have obvious effects on its structure and properties. In order to reveal the specific effects, we heat-treat the original LiCa3Mg(VO4)3 (LCMV) in an oxygen flow with different time to decrease oxygen vacancies, and find that the lattice distortion of [VO4] tetrahedron caused by oxygen vacancy is effectively reduced. Meanwhile, the crystallinity of the treated samples increases, the surface defects decreases, and the fluorescence intensity increases. The variation of photoluminescence quantum yield (PLQY) with oxygen treatment time is as follows: the enhancement effect firstly reaches the strongest (69.34 %) within one hour, then begins to decline after two hours, and finally reaches the platform after three hours and remains basically unchanged. The reason for the enhancement of PLQY is the decrease of oxygen vacancy after one-hour treatment, and the reason for the decrease of PLQY after a further increased treatment time is that the absorption of oxygen and water in air caused by excessive surface defects introduced by oxygen treatment.

Lithium sulfur batteries (LSBs) with high energy density hold some promising applications in the wearable and flexible devices. However, it has been still challenging to develop a simple and feasible approach to prepare flexible LSB cathodes with both robust mechanical strength. Herein, flexible S@C-CNTs cathodes with controllable thicknesses are successfully fabricated via a facile blade-coating method. Due to the strong cohesion among CNTs bundles and the well-designed structure, the flexible S@C-CNTs cathodes are demonstrated to be with a combination of impressive mechanical strength and enhanced electrochemical performance. For the flexible S@C-CNTs cathodes with the sulfur mass loading of 4 mg cm−2, the areal capacity is close to 3.0 mA h cm−2, and the breaking stress is up to 5.59 MPa with 7.77% strain. Meanwhile, the pouch cell exhibits excellent cyclic stability at both flat/bent conditions. All demonstrate that the flexible S@C-CNTs cathodes may satisfy the demands of practical application. Moreover, this methodology is suitable for designing other flexible battery electrodes, such as flexible Si@C-CNTs anodes for lithium ion batteries, flexible P@C-CNTs anodes for sodium/potassium ion batteries, etc.

In this work, a new kind of CdS–ZnO core–shell nanorods with controlled ZnO shell are first synthesized by a simple chemical deposition method in aqueous solution. The thickness and distribution of the ZnO shell can be accurately adjusted, and intimate contact interfaces between CdS and ZnO are well constructed. The optimal CSZ0.5 core–shell heterostructure exhibits a photocatalytic H2 evolution rate of 805.5 μmol h−1 without co-catalysts (3 mg of catalyst, equal to 268.5 mmol g−1 h−1), which is 12 and 895 times higher than that of CdS and ZnO, respectively, and is the maximum value among CdS-based photocatalysts under similar experimental conditions. The significant enhancement in the photocatalytic H2 evolution rate can be mainly attributed to three positive factors: the single-crystalline structure of CdS, the Z-scheme mechanism formed between CdS and ZnO, and the introduced ascorbic acid. The first two factors effectively promote the separation and migration of charge carriers, and the latter factor realizes efficient hydrogen spillover for CdS/ZnO to accelerate the photocatalytic hydrogen evolution reaction. In addition, the homogeneous ZnO shell grown on the CdS core efficiently suppresses the photo-corrosion of CdS, which endows CdS/ZnO with outstanding photostability.

Iron vanadate (FeVO4) nanorods are used as a carrier to support manganese (Mn) and cerium (Ce) oxides for the selective catalytic reduction (SCR) of nitrogen oxides (NOx) with NH3 for the first time. Among these developed Ce–Mn/FeVO4 catalysts with different molar ratios of Ce/Mn, the Ce0.2Mn0.2/FeVO4 catalyst exhibits the best de-NOx performance and N2 selectivity, which are higher than 90% in a wide temperature window of 90–420 °C. Through a series of characterization techniques, it is found that the synergistic effect between Ce and Mn enhances the reduction ability and the number of acid sites on the catalyst, which facilitates the adsorption and conversion of flue gas. The introduction of an appropriate ratio of Ce/Mn increases the concentration of Mn4+ and chemisorbed oxygen (OS) on the catalyst, leading to a “fast SCR reaction” with oxidizing NO to NO2, which significantly improves the low-temperature de-NOx efficiency. In addition, the interaction between the active components (Ce/Mn) and the support (FeVO4) increases the de-NOx performance of Ce0.2Mn0.2/FeVO4 at high temperatures. In the meantime, the Mn4+ + Ce3+ ↔ Mn3+ + Ce4+ reduction electron pair formed between Ce and Mn promotes the transport of electrons, which is also beneficial for the SCR reaction at low temperature. The in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) reveals that the SCR reaction over Ce0.2Mn0.2/FeVO4 catalyst follows both Eley–Rideal (E–R) and Langmuir–Hinshelwood (L–H) reaction mechanisms.

We report a facile solvothermal synthesis of hollow TiO2 nanospheres using phenolic resin nanospheres as templates under magnetic stirring conditions, followed by annealing. The as-prepared hollow TiO2 nanospheres show an inner diameter of ∼400 nm, a shell thickness of ∼45 nm, and a high specific surface area of 33.8 m2 g−1. When used as anode materials for lithium-ion batteries and sodium-ion batteries, the hollow TiO2 demonstrates excellent cycling stability and rate capability, delivering high lithium storage capacities of 178/138 mA h g−1 at 0.2/1.0 A g−1 after 200/1000 cycles, and high sodium storage capacities of 213/177/115 mA h g−1 after 200/1000/4000 cycles at 0.2/1.0/5.0 A g−1. The outstanding electrochemical performance is related to the robust structural stability of the hollow nanostructured TiO2, which can be expected as a promising anode material for next generation alkali metal ion batteries.

In recent years, ternary heterostructures (HSs) composed of three semiconductors have attracted significant attention because of the effective separation and transfer of photogenerated electrons and holes in these materials. In this work, new ternary CdS/ZnS/ZnO (CZZ) HSs with one-dimensional (1D) nanofiber morphology have been successfully fabricated for the first time by a series of processes: electrospinning ZnO nanofibers, sulfurizing ZnO in situ to form ZnS/ZnO binary HSs, and depositing CdS quantum dots in situ on the ZnS/ZnO HSs. Benefiting from the efficient separation and transfer of photoinduced charge carriers, the optimized CZZ ternary HSs exhibit a hydrogen evolution rate of 51.45 mmol h−1 g−1 (quantum efficiency: 26.88% at 420 nm) without any co-catalyst, which is 93.54 and 2.28 times higher than those exhibited by pristine ZnO and ZnS/ZnO binary HSs, respectively, under the same conditions. Furthermore, the rate of hydrogen evolution over the 1D CZZ nanofibers is significantly higher than that over 2D CZZ nanosheets (27.25 mmol h−1 g−1, in the presence of a Pt co-catalyst) prepared by the same sulfurization and deposition procedures. This can be ascribed to the significantly smaller geometric sizes of 1D nanofibers compared to those of 2D nanosheets, resulting in effectively suppressed recombination of photogenerated charge carriers and promotion of photocatalytic H2 evolution performance.

NOx emissions are a major environmental problem, and the selective catalytic reduction (SCR) is the most effective method to convert NOx in flue gas into harmless N2 and H2O. In this work, a new carrier, CuCeOy microflower assembled from a large number of copper-cerium mixed oxide nanosheets, is firstly developed to load vanadium-tungsten mixed oxides (VWOx) for the SCR of NOx with NH3. The resultant optimal VWOx/CuCeOy catalyst exhibits significantly enhanced low-temperature de-NOx performance with the NOx conversion of 60% at 180 °C, over 90% from 240 °C to 390 °C under the gas hourly space velocity (GHSV) of 36,000 h−1. The reason can be mainly attributed the fact that the transfer of electrons among Ce, Cu and V ions is very easy to occur via the following equations Ce3++Cu2+ ↔ Ce4++Cu+, V5+ + Cu+ ↔ V4+ + Cu2+, V4+ + Ce4+ ↔ V5+ + Ce3+, which effectively decreases the apparent activation energy (Ea = 16.59 kJ/mol) of NH3-SCR de-NOx reaction. In addition, the enhanced reducibility and a large number of Bronsted acid sites also contribute the low-temperature de-NOx performance. Both Eley-Rideal and Langmuir-Hinshelwood mechanisms are included in the NH3-SCR de-NOx reaction over the VWOx/CuCeOy catalyst.

Photocatalytic hydrogen evolution from water splitting presents an attractive prospect in dealing with the energy crisis, but the low efficiency of charge separation and migration still seriously hinders its further practical application. Here, an acidified boron-doped g-C

The rapid separation and transfer of photogenerated charge carriers are the essential criteria for high photocatalytic efficiency. Heterostructures (HSs) composed of several semiconductors can take advantage of energy level difference to promote the separation and transfer of photogenerated electrons and holes, where the interface between semiconductors is the most critical position which directly determines the transfer mechanism of photogenerated charge carriers, and ultimately determines the photocatalytic efficiency. Herein, an ultrathin Al2O3 bridging layer is intentionally introduced into the interface between CdS and ZnO by using an atomic layer deposition (ALD) method, and the resultant CdS@Al2O3@ZnO catalyst exhibits a significantly enhanced H2 evolution rate (1190 μmol h−1 m−2) and a high apparent quantum efficiency (AQE, 31.14% at a wavelength of 420 nm). It is revealed that the ultrathin Al2O3 bridging layer converts the original Z-scheme mechanism of photogenerated charge carriers in the CdS@ZnO catalyst into a modified type II mechanism in the CdS@Al2O3@ZnO catalyst, where the photogenerated electrons are tunnelled from the CdS core to the ZnO shell and then are depleted by H2O effectively in time to produce H2. Meanwhile, the photogenerated holes are consumed efficiently by the fixed negative charges of Al2O3. Detailed characterization reveals that the lattice mismatch between wurtzite ZnO and wurtzite CdS is effectively passivated by the Al2O3 interlayer, facilitating the uniform deposition of the ZnO layer, which promotes the close contact between interfaces, suppressing the recombination of charge carriers. This work provides a new strategy for controlling the dominant transfer mechanisms of photogenerated electrons and holes in HSs through interface regulation.

In this work, a new kind of CdS/CdSe/CuS hollow nanospheres (HNPs) is successfully synthesized by one-step synthesis via vulcanization and selenization in aqueous solution, without using any additional templates, for the first time. The three components of CdS, CdSe and CuS in the HNPs are thoroughly combinated with each other at nano-scale, which creates a large quantity of intimate contact interfaces. As a result, the optimal CdSe30Cu2S HNPs exhibit an excellent photocatalytic H2 evolution rate of 723 μmol h−1 (10 mg of catalyst) without adding any noble metal co-catalysts, which is 6.5 times higher than that of the pristine CdS HNPs. The hollow structure enhances the light absorption and provides the inner surface as active sites for the infiltrated water to receive the inner-shell electrons quickly for H2 evolution and the CdS/CdSe/CuS heterostructure with CuS acting as the co-catalyst forms three charge transfer pathways to promote the separation and migration of the photo-induced electrons and holes, resulting in the enhanced photocatalytic performance. This work may provide a strategy for the design and synthesis of other photocatalysts for highly efficient H2 evolution.

Recently, Mn-based catalysts doped/modified by rare earth elements for the selective catalytic reduction (SCR) of NOx with NH3 are becoming a new research hotspot. In current work, Dy-doped MnFe oxides with the morphology of one-dimensional nanowire are successfully prepared by using electrospinning method for the first time, and the catalytic performances for the NH3-SCR of NOx are investigated in detail. It is found several positive factors are introduced due to the doping of Dy with an appropriate amount, such as the enhanced surface Mn4+ concentration and surface chemical adsorption of oxygen, the increased adsorption capacity for NH3 and NO. Theoretical calculation reveals that the Dy-doping causes the larger depletion of electron density of mainly O atoms on the surface of MnFeDy than that of MnFe case, which energetically favors the adsorption of NH3 and NO molecules. Our results fully confirm that Dy is an effective doped element of Mn-based catalysts for developing SCR catalysts with excellent low-temperature de-NOx performance.

CoMoO4 nanoparticles have been successfully in-situ formed and simultaneously embedded within the porous carbon nanofibers (CoMoO4/CNFs) via a facile electrospinning-annealing strategy. The porous CoMoO4/CNFs exhibit a specific surface area of 255.3 m2/g and a pore volume of 0.52 cc/g with average pore diameter of 43.5 nm. The carbon content in the CoMoO4/CNFs can be readily controlled by adjusting the annealing temperature. When examined as anode materials for lithium ion batteries (LIBs), the CoMoO4/CNFs demonstrate superior electrochemical performance, delivering a high reversible capacity of 802 mA h/g after 200 cycles at 200 mA/g and a high-rate capacity of 574 mA h/g at 2000 mA/g. The excellent lithium storage behavior can be attributed to the incorporation of CoMoO4 nanoparticles into the porous N-doped graphitic carbon nanofibers, which efficiently buffer the volume changes of CoMoO4 upon lithiation/delithiation and maintain the overall electrode conductivity/integrity.

A novel MnOx–TiO2 catalyst with hollow silkworm structure was synthesized successfully via an ethanol-thermal strategy by using activated carbon fiber felt as template for the first time. The silkworm-like MnOx–TiO2 catalyst (MnTi) exhibited higher NOx conversion in the whole experimental temperature region (90–330 °C) under a high space velocity of 36,000 h−1 in comparison with the common MnOx–TiO2 catalyst without hollow silkworm structure (MnTi-B). The excellent catalytic performance of MnTi can be attributed to its high specific surface area, large content of active surface oxygen species (OS), and more surface acid sites. In addition, the MnTi catalyst also exhibited excellent resistance to water or SO2 poisoning.

A series of dandelion-like Fe-CeO2/CdS (FeCex/Cdy) nanoflowers with different molar ratios of Fe-CeO2 to CdS are synthesized by solvothermal method for the first time. The FeCex/Cdy nanoflowers are assembled by a large number of nanoparticles with the diameter of about 3 nm, and the introduction of Fe ions and the couple of CdS quantum dots (QDs) efficiently enhanced the relative percentage of Ce3+ in CeO2. The as-obtained FeCe1/Cd1 heterostructure exhibits the highest photocatalytic H2 evolution ability of 108.9 μmol/h, which is 20.5, 6.1 and 7.1 times higher than CeO2, Fe-CeO2 and CdS, respectively. This significantly enhanced photocatalytic performance can be mainly attributed to the synergy between the electronic anchoring effect of Fe3+/Fe2+ and Ce4+/Ce3+ redox couples and the internal electric field constructed by the II-type heterojunction between Fe-CeO2 and CdS. This work provides a new idea for the design of efficient photocatalysts by combining the advantages of heterostructure and ion anchoring effect.

We report an amorphorization-hybridization strategy to enhance lithium storage by casting atomically mixed amorphorized SnO2/MoO3 into porous foam-like carbon nanoflakes (denote as SnO2/MoO3@CNFs, or SMC in short), which are simply prepared by annealing tin(II)/molybdenum(IV) 2-ethylhexanoate within CNFs under ambient atmosphere at a low temperature (300 °C). The SnO2/MoO3 loading amount within CNFs can be easily adjusted by controlling the Sn/Mo/C precursors. When examined as lithium ion battery (LIB) anode materials, the amorphorized SnO2/MoO3@CNFs with carbon content of 32 wt% (also denote as SMC-32, in which the number represents the carbon content) deliver a high reversible capacity of 1120.5 mA h/g after 200 cycles at 200 mA/g and then 651.5 mA h/g after another 300 cycles at 2000 mA/g, which is much better than that of the crystalline SnO2/CNFs (carbon content of 34 wt%), MoO3/CNFs (carbon content of 22.7 wt%), or SnO2/MoO3@CNFs (with lower carbon contents of 11 and 25 wt%). The electrochemical measurements as well as the ex situ structure characterization clearly suggest that combination of amorphorization and hybridization of SnO2/MoO3 with CNFs synergistically contributes to the superior lithium storage performance with high pseudocapacitive contribution.

Element doping has been extensively employed to modulate the physicochemical properties of semiconductors. In this work, Se-doped CdS quantum dots (QDs) with varied Se doping level are fabricated via a solvothermal procedure. Due to the introduction of Se, the Fermi level position of CdS is elevated to a higher position, leading to the effective capture of photogenerated electrons by the trapping sites, which greatly inhibits the recombination of electron-hole pairs and thus prolong the charge carriers’ lifetime. Furthermore, due to the introduction of Se, the density of charge carriers in CdS is significantly enhanced, which is conducive to the production of more photo-generated electrons and holes. It is because of the two favorable factors that the photocatalytic performance of the resultant CdS0.9Se0.1 QDs is greatly improved with a remarkable hydrogen evolution rate of 29.12 mmol h−1 g−1 under simulated solar irradiation (320–780 nm) without any co-catalysts, which is 23.5 times that of the pristine CdS QDs under the same conditions. Moreover, the apparent quantum efficiency (AQE) over CdS0.9Se0.1 QDs reaches 27.1% at 400 nm without co-catalyst addition. This work confirms the feasibility of suppressing the recombination of electron-hole pairs by adjusting the capture level with impurity doping for exploring highly efficient photocatalysts.

Interfacial manipulation of nanostructured heterojunction photocatalysts to enhance charge separation and transfer is highly desirable to achieve a high photocatalytic activity. In this work, a well-designed non-noble-metal Mo2C@C/g-C3N4 heterostructure is constructed, in which the intercalated carbon nanosheets serve as a binder to form an excellent interfacial contact between Mo2C and g-C3N4. In addition, large quantities of carbon quantum dotsare found to be homogeneously embedded in the carbon nanosheets. The as-obtained Mo2C@C/g-C3N4 hybrid exhibits a remarkably improved photocatalytic H2 evolution rate of 52.1 μmol h−1 under visible-light irradiation (λ ≥ 420 nm) without co-catalyst, which is up to nearly 260 times higher than that of pristine g-C3N4 (0.2 μmol h−1) under the same conditions. The significant increase in photocatalytic activity mainly results from the fast charge migration and separation between Mo2C and g-C3N4 facilitated by the conducting carbon nanosheets as an efficient electron mediator. Moreover, the carbon quantum dots embedded in the carbon support also promotes solar energy utilization. This work highlights a feasible strategy to explore highly efficient photocatalysts via interfacial engineering on heterojunction composites.

A new variety of CdS/NiO core-shell p-n heterojunction is synthesized by in-situ chemically depositing NiO shell on single-crystal CdS nanorods for the first time. With this method, the range of NiO shell thickness can be accurately controlled within a few nanometers. The optimized CdS/NiO sample (CSN

Bioinspired nanoconfined catalysis has developed to become an important tool for improving the performance of a wide range of chemical reactions. However, photocatalysis in a nanoconfined environment remains largely unexplored. Here, we report the application of a free-standing and flow-through carbon nitride nanotube (CNN) membrane with pore diameters of 40 nm for confined photocatalytic reactions where reactants are in contact with the catalyst for 5 s–1. Such high rates are otherwise only known for special enzymes and are clearly attributed to the confinement of the studied reactions within the one-dimensional nanochannels of the CNN membrane. Namely, a concave surface maintains the internal electric field induced by the polar surface of the carbon nitride inside the nanotube, which is essential for polarization of reagent molecules and extension of the lifetime of the photogenerated charge carriers. The enhanced flow rate upon confinement provides crucial insight on catalysis in such an environment from a physical chemistry perspective. This confinement strategy is envisioned not only to realize highly efficient reactions but also to gain a fundamental understanding of complex chemical processes.

Metal-organic frameworks (MOFs)/semiconductor hybrids have attracted attention in photocatalysis. Herein, we report a new strategy to use thiol-laced UiO-66 (UiO-66-(SH)2) as a porous and functional support for anchoring CdS quantum dots (QDs) (size: 0.5/3 nm). Cd2+ ions are firstly absorbed into the cavities of UiO-66-(SH)2 MOFs via coordinating to the thiol groups in the presence of a base to produce UiO-66-(S-Cd)2, then thiourea is added to form UiO-66-(S-CdS)2 (abbreviated as UiOS-CdS). It is clearly revealed by ultrafast transient absorption spectroscopy that the thio linkage between UiO-66 and CdS acts as an effective transfer bridge of charge carriers, which greatly promotes the interface transfer process of photogenerated electrons and holes, boosting the photocatalytic hydrogen production performance from water splitting. The optimized UiOS-CdS exhibits a photocatalytic H2 production rate of 153.2 μmol h−1 (10 mg of catalyst) under visible-light irradiation (λ > 420 nm) in the absence of nobel metal co-catalyst, corrsponding to an apparent quantum efficiency of 11.9% at 420 nm. This work may provide an effective strategy to construct QDs-linker-MOFs stylephotocatalysts for efficient energy conversion.

Photocatalytic hydrogen evolution from water splitting driven by visible light is a promising approach to solve energy crisis and environmental problems, and noble-metal-free co-catalysts for boosting the hydrogen evolution reaction are highly desired. Herein, we explore a novel noble-metal-free Fe2P–Co2P co-catalyst for the first time to boost the photocatalytic performance of graphitic carbon nitride (g-C3N4). The resultant Fe2P–Co2P/g-C3N4 with optimum ratio exhibits a hydrogen production rate of 347 μmol h−1 g−1 in the absence of noble-metal co-catalyst, which is 87 times higher than that of pristine g-C3N4 under the same conditions. The significant enhancement in the photocatalytic performance of Fe2P–Co2P/g-C3N4 can be ascribed to the Schottky junction formed between Fe2P–Co2P and g-C3N4, which produces a strong driving force for the transfer of electrons from g-C3N4 to Fe2P–Co2P, promoting the separation and transfer of photogenerated electrons and holes. Furthermore, due to the synergistic effects between the two metal phosphides (Fe2P and Co2P), the Schottky junction in Fe2P–Co2P/g-C3N4 can produce stronger driving force than that in Fe2P/g-C3N4 and Co2P/g-C3N4, resulting in the fact that the hydrogen production rate over Fe2P–Co2P/g-C3N4 is much higher than that over Fe2P/g-C3N4 and Co2P/g-C3N4. This work may shed light on the careful design of co-catalyst by utilizing the synergistic effect of different components.

Crystal facets usually play an important role in the catalytic activity of inorganic single crystals. In this work, two α-Mn2O3 single crystals with an octahedron (exposed with (1 1 1) facet) and a truncated octahedron (exposed with both (1 1 1) and (0 0 1) facets) were successfully prepared by a simple solvent-thermal reaction, and their catalytic activities were evaluated by the selective catalytic reduction (SCR) of NOx with NH3. The results show that the catalytic performance of the α-Mn2O3 single crystal with a truncated octahedron was enhanced in comparison with the α-Mn2O3 single crystal with an octahedron by the exposure of a small fraction of (0 0 1) facets. This can be attributed to the new active sites created by charge redistribution on the surface of the (0 0 1) facets, which provides more adsorption sites, facilitating the further adsorption and reaction of NH3 and NO molecules, and thereby enhancing the catalytic performance. This work should provide new insight into the understanding of crystal-facet-dependent reactivity and important guides for the design and preparation of SCR catalysts with high activity.

1,2-dichloroethane (1,2-DCE) is a representative industrial chlorinated volatile organic compound (CVOC) making great hazardous to the environment and human health. In this work, LaSrMnCoO6 (LSMC) double perovskite-type materials with high thermal stability and coke resistance in 1,2-DCE oxidation were prepared by a facile sol-gel method. Based on this, a series of CrOx/LaSrMnCoO6 catalysts (Cr/LSMC, CrOx loading = 5 to 20 wt.%) which combine the merits of CrOx (high activity and chlorine tolerance) and LaSrMnCoO6 were synthesized and adopted in deep oxidation of 1,2-DCE for the first time. As expected, obvious synergistic effects between CrOx and LSMC on 1,2-DCE destruction were observed. Amongst, 10 wt.% CrOx/LaSrMnCoO6 (10Cr/LSMC) shows the best catalytic activity with 90% of 1,2-DCE destructed at 400 °C. Furthermore, the outstanding catalytic durability and water resistance of 10Cr/LSMC in 1,2-DCE oxidation were also demonstrated. In addition to this, the reaction pathway of 1,2-DCE decomposition over Cr/LSMC materials was discussed based on the results of online product analysis. We found that the enhanced catalytic performance of Cr/LSMC materials can be reasonably attributed to their high reducibility, excellent 1,2-DCE adsorption capability, and large amounts of surface active lattice oxygen species. It can be anticipated that the Cr/LSMC catalysts are promising materials for CVOC elimination and the results from this work could also provide some new insights into the design of catalysts for CVOC efficient destruction.