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The sudden outbreak of coronavirus disease-2019 (COVID-19) sparked widespread concern about organisational resilience in the management domain. The resources, operations and practices of organisational resilience have to be considered in particular contexts at different stages and in relation to numerous inputs, processes and outputs. Selected as one example, the preparation, response and development of a retail supermarket's management and operations in China is examined through an empirical case study. Supply chain and digital construction, improvisational ability, system management and corporate social responsibility all played a positive role in this organisation's response to the outbreak of COVID-19 (2019–2020) in the Chinese management context. Organisational resilience is reflected in the case study organisation's self-interested and altruistic policies and practices. The case provides valuable insights on efficacious management practices for organisational resilience building in the retail industry.

The strong metal-support interaction (SMSI) is widely used in supported metal catalysts and extensive studies have been performed to understand it. Although considerable progress has been achieved, the surface structure of the support, as an important influencing factor, is usually ignored. We report a facet-dependent SMSI of Pd-TiO2 in oxygen by using in situ atmospheric pressure TEM. Pd NPs supported on TiO2 (101) and (100) surfaces showed encapsulation. In contrast, no such cover layer was observed in Pd-TiO2 (001) catalyst under the same conditions. This facet-dependent SMSI, which originates from the variable surface structure of the support, was demonstrated in a probe reaction of methane combustion catalyzed by Pd-TiO2 . Our discovery of the oxidative facet-dependent SMSI gives direct evidence of the important role of the support surface structure in SMSI and provides a new way to tune the interaction between metal NPs and the support as well as catalytic activity.

Understanding surface reconstruction of nanocrystals is of great importance to their applications, however it is still challenging due to lack of atomic-level structural information under reconstruction conditions. Herein, through in situ spherical aberration corrected scanning transmission electron microscopy (STEM), the reconstruction of nanocrystalline SnO2 (110) surface was studied. By identifying the precise arrangements of surface/subsurface Sn and O columns through both in situ bright-field and high-angle annular dark-field STEM images, an unexpected added Sn2O model was determined for SnO2 (110)-(1 × 2) surface. The protruded Snδ+ of this surface could act as the active sites for activating O2 molecules according to our density functional theory (DFT) calculations. On the basis of in situ observation of atomic-level reconstruction behaviors and DFT calculations, an energy-driven reconstruction process was also revealed. We anticipate this work would help to clarify the long-standing debate regarding the reconstruction of SnO2 (110) surface and its intrinsic property.

Anatase TiO2 nanotubes array (ATONA) has attracted tremendous attention owing to its promising applications in solar cells, water splitting and organic pollutants photocatalytic degradation. However, the activity of ATONAs was greatly suppressed by the grain boundaries existed in the tube walls, which acted as carrier scattering and recombination centers. Herein, we report a novel strategy to prepare array of single crystalline anatase TiO2 nanotubes (SC-ATONAs) with significant enhancement of the photocatalytic activity and UV photo response performance compared to the polycrystalline counterparts. The growth of SC-ATONAs was achieved by establishing a crystallization temperature gradient along the tube wall, which ensured the crystallization started from the nucleation of a single nucleus at the bottom of amorphous TiO2 nanotubes prepared by Ti anodization. These findings pave the way to prepare single-crystalline nanotubes with superior performance for other materials.

The anatase TiO2 (001) surface has attracted extensive attention in surface science and for practical applications because of its excellent performance. However, the highly reactive (001) surface usually reconstructs to a (1 × 4)-(001) surface, which may potentially alter its properties. As a result, there are still controversial issues concerning the intrinsic performance of this surface. Recently, significant advances have been made in the surface science study of TiO2 (001), which have elucidated its intrinsic physical and chemical properties. In this review, we summarize our present understanding of the structure and properties of the reconstructed TiO2 (001) surface. First, we provide a brief background of the anatase TiO2 surfaces, including its low-index surface structures and the synthesis of anatase TiO2 nanocrystals with the (001) surface exposed. Next, we focus on the structure, formation mechanism, stability, and surface chemistry of the reconstructed TiO2 (001) surface. Finally, we finish this review by highlighting the current challenges of this subject and providing future research perspectives.

Metal catalysts are of great importance in the modern chemical industry. It is well-known that the structures of metal catalysts determine their properties. However, recent studies suggested that t...

Silicon phosphide (SiP) has attracted a great deal of attention in the field of energy storage because of its unique properties of stable semiconducting two-dimensional structure and promising theo...

Surface oxygen vacancies have been widely discussed to be crucial for tailoring the activity of various chemical reactions from CO, NO, to water oxidation by using oxide-supported catalysts. However, the real role and potential function of surface oxygen vacancies in the reaction remains unclear because of their very short lifetime. Here, it is reported that surface oxygen vacancies can be well confined electrostatically for a polarization screening near the perimeter interface between Pt {111} nanocrystals and the negative polar surface (001) of ferroelectric PbTiO3. Strikingly, such a catalyst demonstrates a tunable catalytic CO oxidation kinetics from 200 °C to near room temperature by increasing the O2 gas pressure, accompanied by the conversion curve from a hysteresis-free loop to one with hysteresis. The combination of reaction kinetics, electronic energy loss spectroscopy (EELS) analysis, and density functional theory (DFT) calculations, indicates that the oxygen vacancies stabilized by the negative polar surface are the active sites for O2 adsorption as a rate-determining step, and then dissociated O moves to the surface of the Pt nanocrystals for oxidizing adsorbed CO. The results open a new pathway for tunable catalytic activity of CO oxidation.

The shape of metal nanoparticles (NPs) is one of the key factors determining their catalytic reactivity. Recent in situ TEM observations show that dynamic reshaping of metal NPs occurs under the reaction conditions, which becomes a major hurdle for fully understanding catalytic mechanisms at the molecular level. This Minireview provides a summary of the latest progress in characterizing and modeling the equilibrium shape of metal NPs in various reactive environments through the joint effort of state-of-the-art in situ environmental transmission electron microscopy experiments and a newly developed multiscale structure reconstruction model. The quantitative agreement between the experimental observations and theoretical modeling demonstrate that the fundamental mechanism of the reshaping phenomenon is driven by anisotropically changed surface energies under gas adsorption. The predictable reshaping of metal NPs paves the way for the rational design of truly efficient nanocatalysts in real reactions.

The anatase TiO2 nanocrystals with dominant (001) facets attracted tremendous attention in the past decade. However, the reported intrinsic property of the (001) surface is still a cause of controversy. A crucial reason is that the (001) surface usually undergoes a (1 × 4) reconstruction, which may result in a remarkable difference in property. Herein, we performed an in situ environmental transmission electron microscopy (ETEM) study regarding the formation and stability of the (1 × 4)-(001) surface of TiO2 nanocrystals. The systematic ETEM studies confirmed that the (1 × 4)-(001) surface could be generated at elevated temperature (above 300 °C) when the surface contaminants were removed and the formed reconstruction could survive under different conditions, which indicate the surface reconstruction should be taken into account in related property research. In addition, an oriented layer-by-layer beam damage process on the (001) surface is confirmed, and optimal imaging conditions were also investigated,...

It is well known that for a nanoparticle the solid-solid phase transition begins with the appearance of a high temperature disordered phase at the surface and the phase interface moves inward gradually with the increase of temperature. However, the size-dependent phase transition behavior remains unclear. Here we report an in-situ TEM study of the phase transition process of different-sized Ag2S nanoparticles at atomic resolution. The onset temperature of disordered phase of the small nanoparticle is found to be lower than that of the big nanoparticle. And, the disordered phase thickness of small nanoparticle is always thicker than that of big nanoparticle. By considering surface and interface free-energy, a phenomenological model based on the minimization of system free-energy is established, which could well explain our experimental results. These discoveries extend our understanding of size dependent phase transition mechanism. Keywords: Solid-solid phase transition, Nanoparticles, In-situ transmission electron microscopy, Ag2S

N2O is a major by-product emitted during low-temperature selective catalytic reduction of NO with NH3 (NH3-SCR), which causes a series of serious environmental problems. A full understanding of the N2O formation mechanism is essential to suppress the N2O emission during the low-temperature NH3-SCR, and requires an intensive study of this heterogeneous catalysis process. In this study, we investigated the reaction between NH3 and NO over a Pd/CeO2 catalyst in the absence of O2, using X-ray photoelectron spectroscopy, NH3-temperature-programmed desorption, NO-temperature-programmed desorption, and in-situ Fourier-transform infrared spectroscopy. Our results indicate that the N2O formation mechanism is reaction-temperature-dependent. At temperatures below 250 °C, the dissociation of HON, which is produced from the reaction between surface H• adatoms and adsorbed NO, is the key process for N2O formation. At temperatures above 250 °C, the reaction between NO and surface N•, which is produced by NO dissociation, is the only route for N2O formation, and the dissociation of NO is the rate-determining step. Under optimal reaction conditions, a high performance with nearly 100% NO conversion and 100% N2 selectivity could be achieved. These results provide important information to clarify the mechanism of N2O formation and possible suppression of N2O emission during low-temperature NH3-SCR.

The strong metal-support interaction (SMSI) is widely used in supported metal catalysts and extensive studies have been performed to understand it. Although considerable progress has been achieved, the surface structure of the support, as an important influencing factor, is usually ignored. We report a facet-dependent SMSI of Pd-TiO

Rotation during reaction Determining changes in heterogeneous catalysts under reaction conditions can provide insight into mechanisms. Under reaction conditions, not only can metal nanoparticles change shape but their interaction with the oxide support could also be affected. Yuan et al. used aberration-corrected environmental transmission electron microscopy to study gold nanoparticles on titanium surfaces at low electron beam doses. During carbon monoxide (CO) oxidation at total pressures of a few millibars and 500°C, they observed that gold nanoparticles rotated by about 10° but returned to their original position when CO was removed. Density function theory calculations indicated that rotation was induced by changes in the coverage of adsorbed molecular oxygen at the interface. Science , this issue p. 517

The interface between metal catalyst and support plays a critical role in heterogeneous catalysis. An epitaxial interface is generally considered to be rigid, and tuning its intrinsic microstructure with atomic precision during catalytic reactions is challenging. Using aberration-corrected environmental transmission electron microscopy, we studied the interface between gold (Au) and a titanium dioxide (TiO

A hexagonal FeSe nanoparticle anode with a novel reaction mechanism and mechanical stability may fully facilitate the desirable rate capability and cycling performance in sodium-ion batteries. In situ TEM reveals that hexagonal FeSe nanoparticle transition to the Fe and Na2Se phase during sodiation, while the products transform to the tetragonal FeSe phase after desodiation.

Layered germanium phosphide (GeP), a recently developed two-dimensional material, promises highly attractive theoretical capacity for use as a lithium-ion battery anode. Here, we comprehensively investigate its electrochemical performance and the modification mechanism. GeP flakes demonstrate large initial discharge/charge capacity and high initial Coulombic efficiency. However, the cycling performance is disappointing in the potential window of 0.001-3 V in which capacity retention is only ∼18% after 100 cycles. In situ transmission electron microscopy reveals that the poor cycling behavior results in the unexpected large volume change induced by complex reaction processes in cycles. Serious cracking and fracture appear clearly on the electrode surface after cycling. Narrowing the working voltage window to 0.001-0.85 V, cycling stability will be greatly enhanced, with 75% capacity retaining after 100 cycles and ∼50% left after 350 cycles due to the absence of the dealloying of Li

Herein, the novel polyaniline@nano hollow carbon sphere (PANI@NHCS) adsorbents with different mass of NHCS were prepared by in-situ polymerization method. The microstructure of obtained PANI@NHCS-10, PANI@NHCS-20, PANI@NHCS-30 and PANI@NHCS-40 samples were observed through both scanning electron microscopy (SEM) and transmission electron microscopy (TEM), which showed that the PANI@NHCS-30 possessed hollow structure like lappaceum shell. Then, the performance of obtained PANI@NHCS-30 was studied for removing hexavalent chromium (Cr(VI)) from waste water. With the help of unique hollow structure and reduction ability of PANI@NHCS-30, the Cr(VI) was fleetly adsorbed and then reduced to less toxic Cr(III). The maximum adsorption capacity was 250.0 mg/g for PANI@NHCS-30 under the optimal condition. Moreover, the effects of initial Cr(VI) concentration, solution pH and different ions on the adsorption performance were investigated in detail. Importantly, the PANI@NHCS-30 still shows superb adsorption ability after five cycles, which suggests its satisfactory reusability ability. The accumulated data revealed the crucial role of PANI and hollow structure co-promoting effect on Cr(VI) reduction reactions over PANI@NHCS-30, which could be applied to the practical use.

Preventing sintering of supported nanocatalysts is an important issue in nanocatalysis. A feasible way is to choose a suitable support. However, whether the metal–support interactions promote or prevent the sintering has not been fully identified. Now, completely different sintering behaviors of Au nanoparticles on distinct anatase TiO2 surfaces have been determined by in situ TEM. The full in situ sintering processes of Au nanoparticles were visualized on TiO2 (101) surface, which coupled the Ostwald ripening and particle migration coalescence. In contrast, no sintering of Au on TiO2 anatase (001) surface was observed under the same conditions. This facet‐dependent sintering mechanism is fully explained by the density function theory calculations. This work not only offers direct evidence of the important role of supports in the sintering process, but also provides insightful information for the design of sintering‐resistant nanocatalysts.

Surface induced order–disorder phase transition has been widely studied on flat bulk surfaces, while such a transition is poorly understood on curved surfaces in nanoscale. Here, we report a direct...

Binders play a significant role in the electrochemical performance of electrodes in batteries, especially for high-capacity conversion/alloying-type electrodes. However, the effects of binders on the electrochemical performance of the conversion/alloying-type anodes in sodium ion batteries are not widely investigated. In this work, we use SnS 2 as a model anode and comparatively investigate the performance of six different types of binders in SnS 2 electrodes of sodium ion batteries by half-cell testing. The binders are sodium carboxymethyl cellulose (CMC-Na), sodium polyacrylate (PAA-Na), CMC-Na-PAA-Na (1:1, wt%, denoted as PAA-CMC), sodium alginate (ALG-Na), PVDF, PTFE. The PAA-CMC binder electrodes exhibit outstanding cycling and rate performance, delivering a reversible capacity of 400 mAh g −1 at the current density of 100 mA g −1 within 70 cycles. Our results indicate that the binder with a large fraction of carboxylate and hydroxyl groups, which lead to stronger hydrogen bonds and/or covalent chemical bonds with the carbon black and active materials, is advantageous for the electrochemical performances of SnS 2 electrodes. The synergistic interactions among the binder and the surface of both the active materials of SnS 2 and the conductive additive of ketjen black have been also schematically proposed in this study.

In this paper, partial density of states and band structures of Anatase's (001) and (101) facets were studied by first-principles calculation. Based on partial density of states, electrons in the (001) facet of Anatase have much higher transition probability to be excited from valence band maximum to conduction band minimum compared with those in an (101) facet, which shows a stronger electronic activity of (001) facet. Besides, the (001) and (101) facets of Anatase have a direct and indirect band structure, respectively, based on the first-principle calculation results. The direct band structure of the (001) facet makes it more suitable to be used in optical detection. Anatase TiO2 nanotubes array modified with (001) exposed nanofacets were grown on Ti substrates by anodization, hydrothermal, and then post annealing. An ultrahigh responsivity as high as 1575.97μA/mW·cm2 under 365 nm ultraviolet light wavelength and 5 V bias was achieved.

We demonstrate an unexpected refacetting process of Pd nanoparticles, induced by N2 under atmospheric pressure at elevated temperatures, by in situ TEM observations. The morphology changes, with a notable increase in the fraction of Pd{110} facets, were visualized by atomic-scale TEM images and further explained by theoretical calculations. Firm evidence and rational understanding revealed that the “inert” gas N2 has the ability to modify the structure of metal nanoparticles. This surprising effect should be considered seriously in vast chemical applications that use N2 as a carrier gas or protective atmosphere.

High-dispersed surface anatase TiO 2 modified CuO X -CeO X catalysts were prepared by wet impregnation method and their activities for selective catalytic reduction of NO with NH 3 were investigated. The structure of TiO 2 was found to influence the interactions between active components and support, which enhanced the NO adsorption and oxidation on catalyst surface under optimal conditions, thus activated the fast SCR reaction at a low temperature of 100 °C.

Nitrogen oxides are one of the major sources of air pollution. To remove these pollutants originating from combustion of fossil fuels remains challenging in steel, cement, and glass industries as the catalysts are severely deactivated by SO

Imaging reactive surface water Recent developments in transmission electron microscopy (TEM) have enabled imaging of single atoms, but adsorbed gas molecules have proven more challenging because of a lack of sufficient image contrast. Yuan et al. adsorbed water and carbon monoxide (CO) on a reconstructed nanocrystalline anatase titanium dioxide (TiO 2 ) surface that has protruding TiO 3 ridges every four unit cells, which provide regions of distinct contrast. Water adsorption on this surface during environmental TEM experiments led to the formation of twinned protrusions. These structures developed dynamic contrast as the water reacted with coexposed CO to form hydrogen and carbon dioxide. Science , this issue p. 428

Layer-by-layer growth played a critical role in the fine design of novel materials and devices. Although it has been widely studied during materials synthesis, the atomic mechanism of the growth remains unclear due to the lack of direct observation at the atomic scale. Here, we report a new mode in layer-by-layer growth via surface reconstruction on MoO

Finite element analysis was used to simulate the current density distributions in the TiO 2 barrier layer formed at the initial stage of Ti anodization. The morphology modification of the barrier layer was found to induce current density distribution change. By starting the anodization with proper TiO 2 barrier layer morphology, the current density distribution can be adjusted to favor the formation of either nanotube arrays or nanopore arrays of anodic TiO 2 . We also found that the addition of sodium acetate into the electrolyte suppressed both the field-assisted chemical dissolution of TiO 2 and the TiF 6 2− hydrolysis induced TiO 2 deposition during anodization, and thus further favored the nanopore formation. Accordingly, highly ordered anodic TiO 2 nanopore arrays, similar to anodic aluminum oxide nanopore arrays, were successfully prepared.

The hexagonal boron nitride nanosheets (BNNSs) are one of the 2-dimensional(2D) materials, and have been explored for their applications in nanoelectronics etc, owing to their unique properties. Here, BNNSs are utilized to develop a high-performance hybrid piezo/triboelectric nanogenerator (PTEG). BNNSs of a few percentages in weight are incorporated into polydimethylsiloxane (PDMS) to form composites that are able to produce piezoelectric voltages up to ~ 5.4 V with d 33 ~ 12 pC/N. A PTEG composed of BNNS-PDMS and polyamide-6 (PA6) membranes ( 20 × 20 mm 2 ) demonstrates a current density of ~ 230 mA m − 2 , an output voltage of ~ 1870 V and a maximum power density of ~ 103.7 W m − 2 , more than three times higher than those of the control PDMS/PA6 nanogenerator. Electric polarization of the BNNS-PDMS membranes can further enhance the output of PTEGs. Detailed investigation reveals that the dramatically enhanced performance originates from the synergy of piezoelectric effect of BNNSs and increased electron affinity of BNNS-PDMS membranes, demonstrates the excellent potential of BNNS-based PTEGs.

Bimetallic core–shell nanoparticles have received considerable attention for their unique optical, magnetic and catalytic properties. However, these properties will be dramatically modified under ambient conditions by their structure and/or composition change. Thus, it is of primary importance to study the complex transformation pathway of core–shell nanoparticles at an elevated temperature. In this work, by using an aberration-corrected scanning transmission electron microscope equipped with an energy dispersive X-ray mapping system, the complete transformation process from a well-designed Pd@Au core–shell nanoparticle to a uniform alloy particle was visualized. It is revealed that this transformation process went through three steps, i.e., surface refacetting, particle resphering and complete alloying. Combining with a developed atomic kinetic Monte Carlo simulation, we found that surface energy is the driving force for shape variation, and the different atomic activation barriers of surface diffusion and bulk migration result in the multistep transformation pathway. Our results offered important information for understanding the structure evolution of bimetallic core–shell nanoparticles, which is beneficial for the rational design of nanoparticles with kinetic stability.

Preventing sintering of supported nanocatalysts is an important issue in nanocatalysis. A feasible way is to choose a suitable support. However, whether the metal-support interactions promote or prevent the sintering has not been fully identified. Now, completely different sintering behaviors of Au nanoparticles on distinct anatase TiO

We demonstrate an unexpected refacetting process of Pd nanoparticles, induced by N

Acquiring the kinetics of gas-nanoparticle fast reactions under ambient pressure is a challenge owing to the lack of appropriate in situ techniques. Now an approach has been developed that integrates time-resolved in situ electron diffraction and an atmospheric gas cell system in transmission electron microscopy, allowing quantitative structural information to be obtained under ambient pressure with millisecond time resolution. The ultrafast oxidation kinetics of Ni nanoparticles in oxygen was vividly obtained. In contrast to the well-accepted Wagner and Mott-Cabrera models (diffusion-dominated), the oxidation of Ni nanoparticles is linear at the initial stage (

SO2-induced deactivation of selective catalytic reduction of NO over CuO–CeO2 was studied. In the case of reaction under low O2 concentration of 1.0 vol%, SO2 severely deactivated the catalyst at 240 °C with a surface S atomic concentration as low as 1.34%. However, the deactivated catalyst could be reactivated during online NO reduction under 5.0 vol% O2 without decreasing the surface S concentration of the catalyst, which could be attributed to the involvement of NO2 in the reactions. NO2 could promote the NO removal through three reaction routes: fast SCR reaction, reaction between NO2 and NH3, and reaction between NO2 and NH4+. Especially under conditions of 10% O2, the reaction between NO2 and NH3/NH4+ induced the formation of extra NHX

ZSM-5 supported highly dispersed FexOy clusters were prepared by a sol–gel method for selective catalytic reduction (SCR) of NO with NH3. XRD, SEM, UV-vis, H2-temperature-programmed reduction (H2-TPR), NH3-temperature-programmed desorption (NH3-TPD), and BET analyses all indicated that Fe species mainly existed as highly dispersed surface FexOy clusters with a Fe3+ concentration of 22 wt%. NO-temperature-programmed oxidation (NO-TPO) revealed that the FexOy clusters promoted the oxidation of NO to NO2, which promoted the low temperature NOX removal. NH3 was activated above 250 °C and over-oxidation of NH3 to NOX was not observed, as a result, a NOX removal efficiency of 91% was achieved at 400 °C. Moreover, the SCR reaction route was found to be temperature dependent, below 200 °C, the NOX reduction followed the reaction between NO2 and non-activated NH3. Fast SCR reaction dominated the NOX removal in the temperature window of 200–325 °C. At temperatures above 250 °C, the normal reaction between activated NH3 and NO compensated the thermodynamic limitation induced suppression of fast SCR.

A synergy between FeOX and CuOX was confirmed in FeCuOX/TiO2-hBN composites for selective catalytic reduction of NO with NH3. Accordingly, the reducibility of composites was modified to promote the NO to NO2 oxidation but suppress the NH3 to NO over oxidation, which is of benefit to the NO reduction. Also the optimal operation temperature could be controlled by tuning the Fe:Cu atomic ratio, and Fe10Ti85BN5, Fe7.5Cu2.5Ti85BN5 and Fe2.5Cu7.5Ti85BN5 achieved the best NO removal above 90% at 375 °C, 300 °C and 250 °C, respectively. From the NO2 and NH3 adsorption behaviors over FeCuOX/TiO2-hBN, the reaction followed Langmuir–Hinshelwood mechanism below 275 °C, but followed Eley–Rideal mechanism above 350 °C. The influence of SO2 on NO removal was found to be temperature dependent, at temperature below 325 °C, slight deactivation was observed, while a promotion was achieved above 350 °C.

Manganese oxide supported on carbon nanotubes (MnOx/CNTs) were prepared by an impregnation method and their catalytic oxidation performances of chlorobenzene (CB) with the assistance of ozone were investigated. The experimental results indicated a synergistic effect between the MnOx/CNTs catalyst and ozone promotion for CB destruction, which promoted CB oxidation at temperatures between 80 °C and 280 °C. Especially at temperatures below 120 °C, both CB conversion and CO2 selectivity above 95% were achieved with an apparent activation energy of 15.0 kJ mol−1. Moreover, MnOx/CNTs showed good stability and resistance to chlorine poisoning, which was demonstrated by stable catalytic activity for a long-term CB catalytic oxidation with 2300 ppm ozone up to 240 h.

Hexagonal boron nitride (hBN) was used as a CuOX/TiO2 catalyst carrier and its effect on NO reduction with NH3 was studied. After hBN was treated with concentrated HNO3, CuOX/TiO2 nanoparticles were dispersed well onto hBN, and the addition of hBN was found to promote NO oxidation, while at the same time suppress NH3 oxidation to NO, and thus promoted the selective catalytic reduction of NO at reaction temperatures between 150 to 350 °C, and a high de-NOX efficiency of 90.6% was achieved at 275 °C. Our study indicates that hBN is a promising catalyst promoter and carrier with excellent stability compared to carbonaceous materials.

Layered germanium phosphide, which combines the advantages of both germanium and phosphorus, is believed to be a potential anode for sodium ion battery. Here, the sodium storage mechanism and electrochemical performance of layered germanium phosphide have been deeply investigated by advanced in-situ transmission electron microscopy technique combining half-cell testing. Dynamic reaction process reveals that individual layered germanium phosphide nanoflake undergoes total area expansion of 248% without any detectable fracture or cracking in sodiation. In contrast, germanium phosphide experiences multi-step reactions, i.e. intercalation and alloying, accompanied by sequentially forming NaxGeP (0

Hydrolytic reaction of TiF 62- induces in situ titanium dioxide (TiO2) nanorings deposition during a TiO2 nanotube array (TONA) preparation by electrochemical anodization. This deposition leads to a reduction of the electric field and the current density beneath the TiO2 nanorings, thus inducing tube wall separation, and results in the formation of a tubular TONA structure. The TiF 62- hydrolytic reaction can also be used to modify the morphology of TONA, which leads to a convenient route to fabricate the novel structures of TONAs for possible new applications.

Interaction between SO2 and titania-carbon nanotubes (CNTs) supported iron-copper oxides catalyst in the absence of NH3 was studied. After the catalyst was pretreated by SO2, S2− ions were detected indicating the existence of a disproportionation reaction of SO2 over catalyst surface. The S species adsorbed on the catalyst surface affected the behaviors of adsorption and oxidation of NH3 and NO, thus influenced the NO reduction route. Over catalysts pretreated at low temperatures, the de-NOx reaction is mainly through the adsorbed NH3 and gaseous NOx. While over catalysts pretreated at high temperatures, the reaction between adsorbed NO and gaseous NH3 becomes the main route. The reduction of Cu2+ to Cu+ by SO2 is a possible reason for catalyst deactivation at low temperatures, but it also suppressed NH3 oxidation, which improved the NO removal efficiency to 81.3% under a GHSV of 150,000 h−1 at 350 °C.

Ozone is found to promote the monochlorobenzene (CB) catalytic oxidation over carbon nanotubes supported copper oxide composite up to reaction temperature of 300 °C. Especially at 250 °C, a CB conversion of 99 %, together with a CO2 selectivity of 98 %, was observed. The selective adsorption of CB, the promotion of Cu+ to Cu2+ oxidation, and the combination of O3 and high temperature activated gas phase O2 are all considered to attribute to the high CB conversion and CO2 selectivity at temperature above 250 °C. Effects of O3 on catalytic oxidation of CB over CuOX/CNTs were studied. A CB conversion of 99 % and a CO2 selectivity of 98 % were achieved at 250 °C, which could be mainly attributed to the synergy between the CB oxidation by O3 and activated O2.