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Metal halide perovskites (MHPs) have not only shown unique merits of ultralow thermal conductivity compared to traditional inorganic thermoelectric (TE) materials, but also featured superior Seebeck effect to organic semiconductors, thereby affording great prospect in TE field. However, their severely poor electrical conductivity significantly hinders TE applications, which results from the restrained doping efficiency due to the limited accommodation capability of heterogeneous dopants and the heavy compensation from interior defects in MHPs. Realizing high‐effectiveness electrical doping in MHPs becomes imperative yet remains extremely challenging. This Minireview is therefore intended to sort out the diversified doping strategies and highlight their underlying impacts on both thermal and electrical transportation in MHPs. These strategies are systematically classified into bulk and surface/interface doping as dictated by where the dopants are implemented while unravelling how they critically impact TE properties in distinctive means. A rational guideline is hence derived to strengthen electrical doping towards desirable perovskite TEs. [ABSTRACT FROM AUTHOR]

A large number of polluting substances, including chlorinated organic substances that were highly stable and hazardous, has been emitted due to the rapidly developing chemical industry, which will affect the ecological environment. Nanocellulose aerogels are effective carriers for adsorption of oil substances and organic solvents, however, the extremely strong hydrophilicity and poor mechanical properties limited their widespread applications. In this study, TEMPO-oxidized cellulose nanofibrils was modified with 2, 4-toluene diisocyanate (TDI) and 4,4′-diphenylmethane diisocyanate (MDI) to prepare strong and hydrophobic aerogels for oil adsorption. The main purpose was to evaluate and compare the effects of two diisocyanates on various properties of modified aerogels. It was found that the modified aerogel had better hydrophobic properties, mechanical properties and adsorption properties. In particular, the modified aerogel with TDI as crosslinker showed a better performance, with a maximum chloroform adsorption capacity of 99.3 g/g, a maximum water contact angle of 131.3°, and a maximum compression stress of 36.3 kPa. This study provides further evidence of the potential of functional nanocellulose aerogel in addressing environmental pollution caused by industrial emissions. [ABSTRACT FROM AUTHOR]

Studies have shown that the cytokine IL-6 plays an important role in the occurrence and development of chronic non-bacterial prostatitis (CNP), but the specific mechanism by which this cytokine regulates CNP is still unclear. At the same time, relevant research have also shown that autophagy is involved in regulating the occurrence and development of inflammation. The possible mechanisms are IL-6/STAT3 signaling pathway and NLRP3 inflammasome. On the basis of establishing the CNP model in rats, we found that IL-6 can regulate autophagy of CNP cells and is associated with the STAT3 pathway and NLRP3 inflammasome. Our results indicate that IL-6 is involved in the regulation of autophagy signaling pathways in CNP. IL-6/STAT3 signaling pathway can suppress cell autophagy pathway in CNP; And the NLRP3 inflammasome may regulate CNP cell autophagy by regulating the IL-6/STAT3 pathway. These findings may provide a new theoretical basis for the pathogenesis of CNP, as well as new ideas and new targets for the treatment and prevention of CNP. [ABSTRACT FROM AUTHOR]

Purpose: To systematically explore the superiority of the transperitoneal approach in robot-assisted partial nephrectomy (TP-RAPN) and retroperitoneal approach in robot-assisted partial nephrectomy (RP-RAPN). Methods: Several databases were searched including PubMed, EMBASE, Cochrane Library, Web of Science, CNKI, CBM, Wan Fang, and VIP to identify relevant studies that reported the comparison of the TP-RAPN and RP-RAPN. Outcomes of data were pooled and analyzed with Review Manager 5.3 to compare the intraoperative and postoperative variables and postoperative complications. Based on the heterogeneity of the studies, odds ratios (ORs) and weighted mean differences (WMDs) with 95% confidence intervals (CIs) were calculated using a random-effect model or fixed-effect model. The sensitivity analysis and the subgroup analysis were used to minimize the effects of heterogeneity. And, publication bias was assessed by funnel plots. Results: In all, 16 studies met the inclusion criteria, including 2336 TP-RAPN patients and 1705 RP-RAPN patients. This meta-analysis reviewed 16 studies on RAPN, and the RP-RAPN showed shorter operative time (OT) (WMD 13.18 minutes; 95% CI 5.04–21.31; p = 0.001), shorter postoperative bowel function recovery (WMD 1.97 days; 95% CI 0.43–3.52; p = 0.01), shorter length of stay (LOS) (WMD 0.51 days; 95% CI 0.25–0.77; p = 0.0001), and lower estimated blood loss (EBL) (WMD 7.08 mL; 95% CI 1.41–12.74; p = 0.01) than the TP-RAPN. Additionally, no significant differences were found in other outcomes. Conclusions: In comparison, the RP-RAPN had significantly shorter OT, postoperative bowel function recovery time, LOS, and lower EBL. The RP-RAPN is associated with better value for posterior and laterally located tumors and is faster and equally safe and low costs for the patient. [ABSTRACT FROM AUTHOR]

CO2 is the main component of greenhouse gases and also an important carbon source. The hydrogenation of CO2 to methane using Ni‐based catalysts can not only alleviate CO2 emissions but also obtain useful fuels. However, Ni‐based catalysts face one major problem of the sintering of Ni nanoparticles in the process of CO2 methanation. Thus, this work has synthesized a series of efficient and robust nickel silicate catalysts (NiPS−X) with different nickel content derived from nickel phyllosilicate by the hydrothermal method. It was found that the Ni loading plays a critical role in the structure and catalytic performance of the NiPS−X catalysts. The catalytic performance gradually increases with the increase of Ni loading. In particular, the highly dispersed NiPS‐1.6 catalyst with a high Ni loading of 34.3 wt% could obtain the CO2 conversion greater than 80%, and the methane selectivity was close to 100% for 48 h at 330 °C and the GHSV of 40,000 mL g−1 h−1. The excellent catalytic property can be assigned to the high dispersion of Ni nanoparticles and the strong interaction between the active component and the carrier, which is derived from a unique layered silicate structure with lots of nickel phyllosilicate and a large number of Lewis acid sites. [ABSTRACT FROM AUTHOR]

Due to the current state of ozone layer depletion and potential risk of skin cancer, researches on sustainable cellulose-based films with ultraviolet (UV) blocking capabilities has attracted widespread attention. However, pure cellulose-based film required UV absorbent to be incorporated because of its poor UV blocking ability. In this work, natural lignocellulosic nanofibril (LCNF) film was fabricated by vacuum filtration and pressing process without any complex chemical modification or adding UV absorbers. The residual lignin retained in LCNF was found to act as natural macro-molecular UV absorber. LCNF film with lignin content of 4.89–15.68% exhibited excellent thermal stability, and their UVA and UVB blocking were in the range of 81.4–99.5% and 96.7–100%, respectively. Moreover, LCNF film exhibited stable UV shielding performance under high temperature, UV irradiation, acidic or alkaline conditions, providing LCNF film with a long-term use capacity. Overall, LCNF film is more environmentally friendly and harmless, which shows high potentials in anti-counterfeiting materials, UV protection, and windshields for vehicles. • LCNF film was fabricated without any chemical modification or adding UV absorbers. • The residual lignin in LCNF was found to act as natural UV absorber. • LCNF film exhibited outstanding UV blocking performance, especially in UVB region. • The UV blocking performance of LCNF film remained stable under robust environment. • LCNF film shows high potentials in clean windows and anti-counterfeiting materials. [ABSTRACT FROM AUTHOR]

Ta-doped Ti1-xTaxCoSb (0≤x≤0.08) half-Heusler compounds were synthesized by melting and annealing process. Their thermoelectric properties were studied in the temperature range of 300–900 K. The Ti1-xTaxCoSb compounds exhibit negative Seebeck coefficients with considerably large absolute values. With increasing Ta substitution, the electrical conductivity was greatly increased, but the thermal conductivity was reduced. Because of the combined effects of increased electrical conductivity and reduced thermal conductivity, the thermoelectric performance of Ti1-xTaxCoSb alloys was apparently improved by doping Ta. The dimensionless figure of merit of 0.3 was obtained for Ti0.92Ta0.08CoSb compound at 900 K. This value is about ten times larger than that of the undoped TiCoSb compound. [ABSTRACT FROM AUTHOR]

Graphical abstract Benefiting from a valuable three-dimensional interconnected micro-, meso- and macroporous nanonetwork, the as-prepared nanonetwork-structured carbon shows surprising formaldehyde gas adsorption properties including super-high storage capacity and ultrafast adsorption rate. Abstract Facile design and construction of advanced materials for eliminating the indoor formaldehyde pollution is still a great challenge but very desirable to provide clean air for human life. Herein, we report a high-performance formaldehyde adsorbent, i.e. , a new type of nanonetwork-structured carbon (NNSC) with a hollow nanosphere as network unit by developing a facile, efficient and post-treatment-free strategy. The NNSCs can be easily obtained by a simple carbonization of a mixture, in which natural wheat husk and Teflon are used as carbon precursor and biotemplate-in-situ-remover, respectively. The as-constructed NNSC exhibits a unique three-dimensional interconnected micro-, meso- and macroporous nanonetwork. Benefiting from such a valuable hollow nanosphere-interconnected network structure, the NNSCs show surprising formaldehyde gas adsorption properties including super-high storage capacity, ultrafast adsorption rate and efficient adsorptively active surface. Remarkably, their specific adsorption capacity and maximum adsorption rate are as high as 120.3 mg g−1 m−3 and 44.6 mg g−1 m−3 h−1, which make 18-fold and 41-fold enhancement when compared to activated carbon commercially used for formaldehyde adsorption, respectively. This work highlights an efficient solution to develop high-performance formaldehyde adsorbents by facile and rational construction of novel porous structure, simultaneously to provide a new avenue to high-value advanced materials for challenging environmental issue. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Porous carbon nanosheets (PCNS) were fabricated by direct carbonization of exfoliated nanopaper-like biomass. • PCNS with simultaneously high surface area (up to 1397 m2/g) and unique hierarchical porous structure was obtained. • A high capacity of 1028 mAh/g at a rate of 0.1 C was achieved. Abstract Two-dimensional porous carbon nanosheet materials are of increasing importance. Many examples for their synthesis exist, but they generally show some common requirements, such as rigid reaction conditions, high cost and complicated multiple synthetic steps. Here we report a facile and cost-effective way to prepare porous carbon nanosheets by using an exfoliated nanopaper-like biomass, i.e. , melaleuca bark as precursor. It is found that just after a simple carbonization treatment, the nanopaper-like barks can be directly transformed into two-dimensional carbon nanosheets with a unique hierarchical porous structure. A high BET surface area of 1397 m2/g can be reached for the obtained carbon materials without any extra activation process. Tuning of nanostructures could be facilely accomplished by varying carbonization treatment conditions. The as-prepared porous carbon nanosheet serves well as the sulfur host materials for lithium-sulfur battery. [ABSTRACT FROM AUTHOR]

Development of efficient, low-cost and high-performance carbon materials as the electrodes is of significance for supercapacitors. Here we report a new class of hierarchical porous carbon with a three-dimensional network morphology of interconnected nanoparticle units prepared by using natural Indicalamus leaves and polytetrafluoroethylene as carbon precursor and silica- in-situ -remover, respectively. This protocol allows for successful post-treatment-free synthesis of biomass-based hierarchical porous carbon with specific surface area as high as 1801 m 2 /g without any extra activation process. Accordingly, when used as the electrodes of aqueous symmetrical supercapacitor, the as-prepared carbon material demonstrates superior capacitive behaviors, including high capacitances of 326 and 211 F/g in 1.0-V and 1.8-V supercapacitors, respectively, high energy density of 23.7 Wh/kg at power density of 224.5 W/kg, and excellent cycling stability. With these extremely attractive capacitive properties, this class of hierarchical porous carbon outperforms many typical state-of-the-art carbonaceous electrodes. [ABSTRACT FROM AUTHOR]

The heteropoly acid (PMo) and Ni in situ encaged in the secondary pore of nanocrystalline HZSM-5 zeolites was prepared from molybdenum oxide and phosphoric acid and nickel nitrate, in a slurry mixture of nanocrystalline HZSM-5 zeolite crystals and deionized water. Catalysts were characterized by ICP, FT-IR, XRD, 31P MAS-NMR, ESR, Py-IR, -TPD, BET, SEM and TEM. PMo cannot enter the interior pores of the zeolite, but becomes encaged in the secondary pore of nanocrystalline HZSM-5 zeolite. The hydroconversion of n-octane over various catalysts was investigated in order to obtain light isomers of alkanes and aromatics products with high octane number. From the results presented in the paper, it is clear that the catalytic properties of the “in situ encaged” PMo–Ni and impregnated PMo–Ni properties are similar, and the number and distribution of Brønsted and Lewis acid sites in these two catalysts are similar, too. It is concluded that both the aromatization of n-octane and the ability of producing light iso-alkanes are enhanced over the PMo and Ni ‘in situ encaged’ and impregnated catalysts than other catalysts. The effects of the acidity and temperature on the activity of n-octane hydroconversion over investigated catalysts are demonstrated. [Copyright &y& Elsevier]

Abstract: 12-Molybdophosphoric acid (PMo), Ni and Ni–PMo loaded on nanoscale HZSM-5 zeolites were prepared and characterized by BET, IR, XRD, Py-IR, NH3-TPD, TG and SEM. The hydroconversion of n-octane over various catalysts was investigated in order to obtain light isomers alkanes and aromatics products with high-octane-number. The acid amounts of the catalysts were modified after the loading of PMo and Ni, and its relation to the activity of the reaction was discussed. It is concluded that the stability of aromatization is improved, and the yield of light iso-alkanes is enhanced due to the introduction of PMo and Ni. The improved activity of n-octane hydroconversion over PMo and Ni loaded nanoscale HZSM-5 zeolites could be attributed to the increase of the acid amounts and the synergetic effect between Brønsted and Lewis acid sites. [Copyright &y& Elsevier]

Abstract: n-Type (Bi2Te3)0.93(Bi2Se3)0.07 thermoelectric materials doped with various content of TeI4 (0, 0.05, 0.10, 0.13, and 0.15wt.%) have been fabricated through the zone melting method. Electrical conductivity (σ), Seebeck coefficient (α) and thermal conductivity (κ) were measured along the crystal growth direction in the temperature range of 300–500K. The influence of the variations of TeI4 content on thermoelectric properties was studied. The undoped (Bi2Te3)0.93(Bi2Se3)0.07 exhibited p-type conduction and it translated to n-type when TeI4 was doped. The increase of TeI4 content increased the carrier concentration and thus resulted in an increase of σ and a decrease of |α|. The maximum figure of merit ZT (ZT=α2σT/κ) of the zone-melted crystals in the direction parallel to the growth direction showed a value of 0.90 for the sample containing 0.10wt.% TeI4. [Copyright &y& Elsevier]

Abstract: Heterostructured polyaniline/Bi2Te3 nanowires have been prepared by chemical and electrochemical reactions on a porous alumina template. Its morphology and structure have been studied by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and electron probe microanalysis. The microscope analysis reveals that Bi2Te3 is well enveloped in polyaniline tubules in pores of alumina template. This microscopic material shows possible application in microthermoelectric device. [Copyright &y& Elsevier]

Abstract: In the present study, p-type (Bi2Te3) x (Sb2Te3)1− x crystals with various chemical compositions (, 0.05, 0.10, 0.16, 0.20, 0.24 and 0.26) were fabricated through the zone melting method. Thermoelectric properties, including Seebeck coefficient (), electrical conductivity () and thermal conductivity (), were measured in the temperature range of 300–500K. The influence of the variations of Bi2Te3 content () on the thermoelectric properties was studied. The increase of Bi2Te3 content () caused a decrease in hole concentration and thus a decrease of and an increase of . The maximum figure of merit () of 1.14 was obtained at about 350K for the composition of 24% Bi2Te3–76% Sb2Te3 with 3wt% excess Te. [Copyright &y& Elsevier]

Abstract: The n-type Bi2(Te,Se)3 thermoelectric materials with preferred grain orientation have been fabricated through the spark plasma sintering (SPS) technique. The c-axis of the grains in the sintered samples were preferentially oriented parallel to the pressing direction, the orientation factor of the (00 l) planes changed from 0.4 to 0.85 with the sintering conditions. The anisotropy was investigated by measuring the electrical conductivities in the two directions perpendicular and parallel to the pressing direction. The optimal figure of merit ZT (ZT = α 2 σT/κ) of the sintered materials in the direction perpendicular to the pressing direction was comparative to that of the zone-melted materials in the same crystallographic direction, while the bending strength reached about 80MPa, which is 7–8 times of that of the zone-melted materials. [Copyright &y& Elsevier]

Abstract: In the present study, p-type (Bi,Sb)2Te3 thermoelectric materials have been fabricated through the spark plasma sintering (SPS) method by using powders with various particle sizes. Electrical conductivity (σ), Seebeck coefficient (α), and thermal conductivity (κ) were evaluated in the temperature range of 300–500K. The effect of annealing of the sintered samples on thermoelectric properties was also investigated. The maximum figure of merit ZT (ZT = α2σT/κ) of the sintered samples in the direction perpendicular to the pressing direction (with c-axis preferred orientation) was 1.15 at about 350K, corresponding to be about 115% of that of the zone-melted ingot with the same composition in the same crystallographic orientation; while the bending strength was highly improved from about 10 to 80MPa. [Copyright &y& Elsevier]

Abstract: Textured p-type (Bi,Sb)2Te3 has been fabricated through zone melting and spark plasma sintering (SPS) techniques. The optimal figure of merit (ZT) of the sintered materials reached 1.15, which was about 115% of that of the zone-melted ingot material. The bending strength was greatly improved (from about 10 to 80MPa). [Copyright &y& Elsevier]

Ca3-xDyxCo4O9+δ (x=0, 0.15, 0.3 and 0.45) polycrystalline samples have been prepared using a sol–gel process followed by SPS sintering. Their thermoelectric properties have been carefully studied from room temperature to 1000 K. The substitution of Dy for Ca results in increasing of both thermopower and electrical resistivity, which could be attributed to the decreasing of carrier concentrations. The Dy substituted samples (x=0, 0.3) have lower thermal conductivity than Ca3Co4O9+δ due to their lower electronic and lattice thermal conductivities. The dimensionless figure of merit ZT reaches 0.27 at 1000 K for the sample of Ca2.7Dy0.3Co4O9+δ. [Copyright &y& Elsevier]

We have prepared polycrystalline Ca3−xEuxCo4O9+δ (x=0, 0.15, 0.3 and 0.45) samples using a sol-gel process followed by SPS sintering and investigated the Eu substitution effects on their high-temperature thermoelectric properties. With the Eu substitution, both the electrical resistivity and thermopower increase monotonously. This could be attributed to the decrease of hole concentrations by substitution of trivalent Eu3+ for divalent Ca2+. The Eu substituted samples (x=0.15, x=0.3) have lower thermal conductivity than Ca3Co4O9+δ due to their lower electronic and lattice thermal conductivity. The dimensionless figure of merit ZT reaches 0.3 at 1000 K for the sample of Ca2.7Eu0.3Co4O9+δ. [Copyright &y& Elsevier]

The study of catalysts supported by polyoxometalates (POMs) with green oxidative desulfurization activity is an important research topic in oil refining. In this paper, a nano-sized H-β zeolite support was modified by tetraethyl orthosilicate (TEOS) and tetrabutyl titanate (TBOT) to form a microporous–mesoporous structure. On this basis, the modified H-β zeolite was used as a support to load POMs with different structures. The characterization results of Fourier transform infrared (FT-IR) spectroscopy, X-ray powder diffraction (XRD), ultraviolet-visible (UV-vis) diffuse reflectance spectroscopy, scanning electron microscopy (SEM), N2 adsorption–desorption, X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy showed that POMs had been successfully loaded onto the support, and the skeleton structures of POMs and zeolites were maintained. The introduction of POMs significantly improved the ODS performance of bulky organic sulfides, especially benzothiophene (BT). The order of catalytic oxidative desulfurization activity of POMs with different structures was: Keggin > Sandwich ≈ Anderson > monovacant Dawson > Dawson > MoO3. Under the optimum reaction conditions: T = 50 °C, t = 1 h, moil : mcatalyst = 35 : 1, and n(O) : n(S) = 13 : 1, the oxidation conversion of BT and dibenzothiophene over the catalyst supported by phosphotungstic acid (HPW) reached 99.9%. The role of titanium active species, peroxide polyoxometalate, and titanium–silicon composite oxides in improving the oxidative removal of organic sulfides was discussed. [ABSTRACT FROM AUTHOR]

Thermoelectric (TE) fibers are more suitable than films for portable or wearable devices. Herein, 2–3 nm thick poly (3,4‐ethylenedioxythiophene): poly (styrenesulfonate) (PEDOT:PSS) layer‐coated tellurium nanowires (PC‐Te NWs) are in situ prepared by a hydrothermal method. Then a series of PEDOT: PSS/PC‐Te NWs composite fibers are prepared by wet spinning and post‐treatment. The nanolayer prevents the agglomeration of the Te NWs and makes the NWs and PEDOT:PSS matrix have good compatibility, which results in the PC‐Te NWs content to a high value of 70 wt% and the fibers still with flexibility. The high aspect ratio of the PC‐Te NWs and the stress from the inner wall of the needle during spinning make the NWs ordered align along the composite fiber. Due to the large content and orientational arrangement of the PC‐Te NWs, as well as effective post‐treatment, an optimized composite fiber shows a power factor of 385.4 µW m−1 K−2 at 300 K, which is ≈4.9 times as high as the highest value of previously reported PEDOT:PSS/Te NWs‐based composite fibers. In addition, the composite fiber has good flexibility. The flexible TE generators assembled have excellent output performance. This work provides an effective strategy for the preparation of high‐performance flexible TE composite fibers. [ABSTRACT FROM AUTHOR]

Investigates the transient clock voltage and heating effects in high-speed gallium arsenide resistive-gate charge-coupled devices. Computation of the transient voltage delays using a circuit model; Analysis of the heating effect of the cermet layer on the leakage currents and the resulting thermally-generated carriers; Observations on the cermet resistivity.

Describes the design and analysis of a high-speed gallium arsenide (GaAs) comparator circuit with less power consumption and area. Use of high-speed GaAs comparator circuit on high-speed A/D conversion and artificial neural networks applications; Analysis of the comparator to determine the effects of threshold deviations on the resolution; Use of controlled sizes of devices to minimize susceptibility to threshold deviations while maintaining optimum performance.

Lignocellulosic nanofibrils (LCNF) production ordinarily requires vigorous chemical reactions and intensive mechanical fibrillation, causing potential environmental pollution. To overcome this issue, economic and green mixed enzymatic treatments were employed to prepare LCNF from unbleached pulp in this work. In contrast to mixed enzymatic post-treatment, pretreatment seems to be a better alternative for cellulose nanofibrillation, endowing LCNF with decreased average height (15.0 nm), higher shear storage modulus (387.3 Pa), and increased thermal stability with the maximal weight loss temperature (T max) of 352 °C. The resultant LCNF was directly used to fabricate films without any chemical modification. It was found that the diameter of LCNF played key roles in affecting the surface morphology of film, for example, films made from fibrils with smaller diameter had smoother surface. Moreover, the tensile stress and Young's modulus of the resulting LCNF film prepared from pretreated fibrils were about 138% and 20% higher than those from post-treated fibrils. Overall, using mixed enzymes in addition to mechanical fibrillation, especially enzymatic pretreatment, is an environment-friendly method to prepare LCNF and films, which provides useful knowledge for low-cost and clean production and facilitates the commercialization and application of nanomaterials. • Cleaner production of LCNF was achieved by enzymatic treatment. • Pretreatment was more suitable for cellulose nanofibrillation. • Pretreatment endowed LCNF with higher viscoelasticity and better thermal stability. • Films made from fibrils with small diameter presented higher mechanical properties. • This work gives us insights into more efficient and reasonable enzymatic treatment. [ABSTRACT FROM AUTHOR]

CoSb3-based skutterudite compounds are promising candidates as advanced thermoelectric (TE) materials used in TE power generation. The electrode fabrication is one of the key techniques in constructing TE elements for the practical application. In the present study, sintering of CoSb3 powder and joining of CoSb3 to molybdenum electrode have been simultaneously performed by spark plasma sintering (SPS) technique. The insertion of Ti interlayer between Mo and CoSb3 is effective to join CoSb3 to Mo by forming an intermediate layer of TiSb at the Ti–CoSb3 boundary and a composition–gradient alloy layer at the Ti–Mo boundary. Potential voltage measurement results indicated that CoSb3/Ti/Mo joint interface has a low electrical resistance. The CoSb3/Ti/Mo joints also have a moderately high shearing strength and high thermal duration stability. [Copyright &y& Elsevier]

To expand the market capacity of p‐diethylbenzene (PDEB), core‐shell zeolite (TS‐1@MCM‐48) is designed as a catalyst for PDEB oxidation. TS‐1@MCM‐48 catalyst is synthesized by in‐situ crystallization method and characterized by X‐ray diffraction (XRD), transmission electron microscope (TEM), scanning electron microscope (SEM), X‐ray photoelectron spectroscopy (XPS), N2 adsorption‐desorption, in‐situ electron paramagnetic resonance (EPR) and 29Si nuclear magnetic resonance (29Si MAS‐NMR). Oxidation of PDEB by H2O2 was investigated systematically in liquid phase. The conversion of PDEB over TS‐1@MCM‐48 was 28.1 % and the total selectivity was 72.6 %, where the selectivity of EAP (p‐ethylacetophenone) and EPEA (4‐ethyl‐α‐methylbenzyl alcohol) was 28.6 % and 44.0 %, respectively. Compared with TS‐1 and MCM‐48 zeolite, the conversion rate of reactants and the selectivity of products have been significantly improved. The catalytic performance of TS‐1@MCM‐48 is derived from its well‐crystallized microporous core and mesoporous shell with regular channels, which make active sites of TS‐1 zeolite in the catalyst be fully utilized and mass transfer resistance be largely reduced. Further through theoretical calculation, we propose that the oxidation of PDEB is the result of the combination and mutual transformation of free radical process and carbocation process. Core‐shell structure ensures the conversion rate of raw materials and improves the selectivity of products. [ABSTRACT FROM AUTHOR]

Power generation modules utilizing thermoelectric (TE) materials are suitable for recycling widespread low‐grade waste heat (<600 K), highlighting the immediate necessity for advanced Bi2Te3‐based alloys. Herein, the substantial enhancement in TE performance of the p‐type Bi0.4Sb1.6Te3 (BST) sintered sample is realized by subtly incorporating the non‐stoichiometric Ag5Te3 and counteractive Se. Specifically, Ag atoms diffused into the BST lattice improve the density‐of‐states effective mass (md*) and boost the hole concentration for the suppressed bipolar effect. The addition of Se further improves md* prompting the room‐temperature power factor upgrade to 46 W cm−1 K−2. Concurrently, the lattice thermal conductivity is considerably lowered by multiple scattering sources exemplified by Sb‐rich nanoprecipitates and dense dislocations. These synergistic results yield a high peak ZT of 1.44 at 375 K and an average ZT of 1.28 between 300 and 500 K in the Bi0.4Sb1.6Te2.95Se0.05 + 0.05 wt.% Ag5Te3 sample. More significantly, when coupled with n‐type zone‐melted Bi2Te2.7Se0.3, the integrated 17‐pair TE module achieves a competitive conversion efficiency of 6.1% and an output power density of 0.40 W cm−2 at a temperature difference of 200 K, demonstrating great potential for practical applications. [ABSTRACT FROM AUTHOR]

Flexible thermoelectrics, including flexible thermoelectric materials and devices, can directly convert the heat from human body into useful electricity, providing a promising solution for uninterrupted power to wearables. In the past decade, flexible thermoelectrics has achieved notable progress. Various kinds of flexible thermoelectric materials have been developed and some of them have been fabricated into flexible thermoelectric devices, showing the ability to generate nW‐level or even μW‐level electricity. Herein, the basic design principles and typical configurations of flexible thermoelectric devices, as well as the requirements on thermoelectric materials to achieve high performance flexible thermoelectric devices, are first introduced. Then, the recent progress achieved in flexible thermoelectric devices based on organics materials, traditional inorganic materials, other organic/inorganic composites/hybrids, and plastic deformable inorganic semiconductors, respectively, are summarized. Finally, an outlook on the future development of flexible thermoelectrics is briefly given. This study sheds light on the further development of flexible thermoelectrics. [ABSTRACT FROM AUTHOR]

Single phases of SrBi2-χNdχNb2O9 (χ=0, 0.1, 0.2, and 0.4) ceramics were prepared by the solid-state reaction method and studied by dielectric and Raman spectroscopy. The substitution of Nd3+ for Bi3+ induced a dielectric relaxation behavior for SrBi2-χNdχNb2O9 (χ=0.1, 0.2, and 0.4). When χ=0.4, the dielectric response of SrBi1.6Nd0.4Nb2O9 is characteristic of typical relaxor ferroelectrics, which could be attributed to the disorder induced by the Nd3+ substituting for Bi3+ in Bi2O2 layers. The dielectric relaxation of SrBi1.6Nd0.4Nb2O9 was fitted using the Vögel-Fulcher relationship, which indicates that SrBi1.6Nd0.4Nb2O9 is analogous to a spin glass with thermally activated polarization fluctuations above a static freezing temperature. Raman spectra of SrBi2-χNdχNb2O9 ceramics could indicate that the structural distortion of NbO6 octahedron decreases with the increase in Nd content, which results in the decrease in Tm for SrBi2-χNdχNb2O9 ceramics. [ABSTRACT FROM AUTHOR]

In this work, we report the ternary Cu-based chalcogenide, Cu2TiTe3, as a promising thermoelectric material in middle-temperature range. The bonding interaction between Te p and Ti d states is observed in the Ti–Te octahedron, which drives the side bands up converging with Γ band, yielding a high valence band degeneracy of 5. A high electronic quality factor of 2.2 μW cm−1 K−2 and a decent power factor of 7.5 μW cm−1 K−2 at 300 K are achieved for Cu2TiTe3. Likewise, Cu2TiTe3 demonstrates low lattice thermal conductivity throughout the measured temperature range, which is attributed to the low frequency vibration related to the global motion of Ti–Te–Cu clusters. Finally, a maximum figure-of-merit of 0.38 was obtained for Cu2TiTe3 at 600 K. [ABSTRACT FROM AUTHOR]

Recently, defective three-quarter Heusler compounds MCo1.5Sn (M = Ti, Zr, and Hf) have been reported with interesting crystal structure differing from the traditional half-Heusler and full-Heusler compounds. These defective compounds are metallic ferromagnets, but the detailed correlation between magnetic and electrical transport properties is still unclear. In this study, we dope Cu in ZrCo1.5Sn to dilute the magnetic Co atoms with the purpose of clarifying how the magnetism influences the electrical transport properties in the defective three-quarter Heusler compounds. Significantly lowered ferromagnetic transition temperature and decreased saturated magnetic moment are observed in Cu-doped ZrCo1.5Sn due to the diluted Co atoms. Likewise, in the ferromagnetic phase, the dominant carrier scattering mechanism is changed from spin fluctuation scattering to magnetic impurity scattering. The doped Cu atoms introduce non-bonding states below the valence band maximum, resulting in the appearance of a narrow bandgap around 0.1 eV. Correspondingly, the electric transport behavior in the paramagnetic phase shows a semiconducting character with a negative temperature dependence of resistivity. This study provides further understanding to the correlation between magnetic properties and electrical transport properties in defective Heusler-based compounds. [ABSTRACT FROM AUTHOR]

The combustion of sulfur-containing fossil fuels has led to excessive emissions of SOx, and the oxidative deep desulfurization of fuels has rapidly attracted the interest of researchers. The TS-1@TiO2-x support was fabricated via a simple titanium alkylation method, and the HPW/TS-1@TiO2-0.05 catalyst was successfully obtained by impregnation of phosphotungstic acid (HPW) on the support. The characterization of the synthesized materials was conducted by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Ultraviolet-visible diffuse reflectance (UV-vis DRS), Raman spectroscopy, scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), and N2 adsorption–desorption. The characterization results showed that the catalyst retained the Keggin structure of HPW and the MFI structure of the support and also proved the interaction between HPW and the support. The catalytic performance of the prepared catalysts was investigated for the oxidative desulfurization of the model oil, including thiophene (TH), benzothiophene (BT), and dibenzothiophene (DBT), with hydrogen peroxide as an oxidant. During the ODS process, the loading amount of TiO2, reaction temperature, reaction time, catalyst dosage, and molar ratio of O and S were optimal with values of 5%, 60 °C, 90 min, 0.06 g, and 12 : 1, respectively. The conversion rates of three organic sulfides with different sizes (TH, BT, and DBT) over HPW/TS-1@TiO2-0.05 were 99.9%, 78.8%, and 99.9%, respectively. Furthermore, a possible ODS reaction pathway over HPW/TS-1@TiO2-0.05 is proposed. [ABSTRACT FROM AUTHOR]

Ge-Sb-Te compounds (GST), the well-known phase-change materials, are considered to be promising thermoelectric (TE) materials due to their decent thermoelectric performance. While Ge2Sb2Te5 and GeSb2Te4 have been extensively studied, the TE performance of GeSb4Te7 has not been well explored. Reducing the excessive carrier concentration is crucial to improving TE performance for GeSb4Te7. In this work, we synthesize a series of Se-alloyed GeSb4Te7 compounds and systematically investigate their structures and transport properties. Raman analysis reveals that Se alloying introduces a new vibrational mode of GeSe2, enhancing the interatomic interaction forces within the layers and leading to the reduction of carrier concentration. Additionally, Se alloying also increases the effective mass and thus improves the Seebeck coefficient of GeSb4Te7. The decrease in carrier concentration reduces the carrier thermal conductivity, depressing the total thermal conductivity. Finally, a maximum zT value of 0.77 and an average zT value of 0.48 (300–750 K) have been obtained in GeSb4Te5.5Se1.5. This work investigates the Raman vibration modes and the TE performance in Se-alloyed GeSb4Te7 sheddinglight on the performance optimization of other GST materials. [ABSTRACT FROM AUTHOR]

Li-ion batteries are a key technology for addressing the global challenge of clean renewable energy and environment pollution. Their contemporary applications, for portable electronic devices, electric vehicles, and large-scale power grids, stimulate the development of high-performance battery materials with high energy density, high power, good safety, and long lifetime. High-throughput calculations provide a practical strategy to discover new battery materials and optimize currently known material performances. Most cathode materials screened by the previous high-throughput calculations cannot meet the requirement of practical applications because only capacity, voltage and volume change of bulk were considered. It is important to include more structure-property relationships, such as point defects, surface and interface, doping and metal-mixture and nanosize effects, in high-throughput calculations. In this review, we established quantitative description of structure-property relationships in Li-ion battery materials by the intrinsic bulk parameters, which can be applied in future high-throughput calculations to screen Li-ion battery materials. Based on these parameterized structure-property relationships, a possible high-throughput computational screening flow path is proposed to obtain high-performance battery materials. [ABSTRACT FROM AUTHOR]

Diamondlike compound Cu2SnS3 has attracted great attention recently due to its excellent thermoelectric performance and the features of being eco-friendly and low cost. However, the underlying mechanism for its good electrical transports under high carrier concentration range is still not clear. In this work, we synthesized a series of Cu2+xSn1−xS3 (x = 0–0.08) samples. These nonstoichiometric Cu2+xSn1−xS3 samples are polymorph simultaneously crystalizing in the monoclinic, tetragonal, and cubic structures. The characterization on the electrical transports and the analysis on the band structure reveal that the large density-of-states effective mass, high Seebeck coefficient, and high mobility under a high carrier concentration in the Cu2+xSn1−xS3 system are originated from the existence of multiple bands near the edge of the valence band. Likewise, the polymorphic structure has little influence on the electrical transports. A maximum power factor of 12.6 μW cm−1 K−2 at 700 K has been obtained for the nonstoichiometric Cu2.08Sn0.92S3. Combining the low lattice thermal conductivity of these samples, Cu2.08Sn0.92S3 shows a peak dimensionless figure of merit of 0.5 at 700 K. This work is helpful for guiding the future optimization of thermoelectric performance on Cu2SnS3. [ABSTRACT FROM AUTHOR]

Li-ion batteries are a key technology for addressing the global challenge of clean renewable energy and environment pollution. Their contemporary applications, for portable electronic devices, electric vehicles, and large-scale power grids, stimulate the development of high-performance battery materials with high energy density, high power, good safety, and long lifetime. High-throughput calculations provide a practical strategy to discover new battery materials and optimize currently known material performances. Most cathode materials screened by the previous high-throughput calculations cannot meet the requirement of practical applications because only capacity, voltage and volume change of bulk were considered. It is important to include more structure–property relationships, such as point defects, surface and interface, doping and metal-mixture and nanosize effects, in high-throughput calculations. In this review, we established quantitative description of structure–property relationships in Li-ion battery materials by the intrinsic bulk parameters, which can be applied in future high-throughput calculations to screen Li-ion battery materials. Based on these parameterized structure–property relationships, a possible high-throughput computational screening flow path is proposed to obtain high-performance battery materials. In this review, we discuss some quantitative descriptions of structure–property relationships by the intrinsic bulk parameters, which can be applied in the future high-throughput computational screening to obtain high-performance Li-ion battery materials. [ABSTRACT FROM AUTHOR]

In this paper, the desired speed is figured out as an important parameter for ordinary differential equation (ODE) based pedestrian simulation models. However, there lacks a thorough study on the optimal way of assigning the desired speed for ODE based pedestrian simulation models to achieve reliable performance. To gain a deep understanding of the role of the desired speed and its influence on the performances of the ODE based pedestrian simulation models, a total of nine assigning strategies of the desired speed are conducted a comparison study. Specifically, the performances of the ODE based models equipped with such desired speed assigning strategies are compared with regard to reference data from both the uni- and bi-directional pedestrian flow scenarios using a fair model comparison framework. Then, the performances are compared across several dimensions, including different assigning strategies of the desired speed, the different pedestrian simulation models, different experiments for the same motion base, and different motion base scenarios. Based on these results, four findings are summarized. Firstly, the desired speed is quantitatively verified to be an important role in the performance of ODE based pedestrian simulation models. Secondly, pedestrian density level is verified to be an effective indicator for the complexity of pedestrian crowd dynamics. Thirdly, the performance of the ODE based models is dependent on the extent to which the heterogeneity of desired speed is considered. Lastly, the performance of the social force model (SF) is suggested to be more predictable than optimal reciprocal collision avoidance model (ORCA) regarding the stability and optimality. Finally, based on the above findings, recommendations on assigning the desired speed for ODE based pedestrian simulation models are given. • The desired speed is recognized as an important affecting parameter for the performance of the ODE based pedestrian simulation models. • A total of nine desired speed assigning strategies are compared regarding their influence on the performance of the ODE based models. • Tentative suggestions on assigning the desired speed for the ODE based models are provided. [ABSTRACT FROM AUTHOR]

As the pseudo-binary alloys between GeTe and Sb2Te3, GeSbTe-based compounds are promising thermoelectric materials. Although Ge2Sb2Te5 and GeSb2Te4 have widely been studied, the thermoelectric properties of GeSb4Te7 have not been well understood yet. In this work, we design a series of GeSb4-xBixTe7 solid solutions and systematically study the variation in the crystal structure, electrical, and thermal transport properties. Alloying Bi effectively reduces the carrier concentration and, thus, enhances the Seebeck coefficient. Meanwhile, the thermal conductivity is greatly reduced via large mass fluctuations. A maximum zT of 0.69 at 550 K and an average zT value of 0.52 between 300 and 700 K have been achieved for GeSb1.5Bi2.5Te7. These findings will promote the understanding and development of GeSbTe-based thermoelectric materials. [ABSTRACT FROM AUTHOR]

The recently discovered ductile/plastic inorganic semiconductors pave a new avenue toward flexible thermoelectrics. However, the power factors of current ductile/plastic inorganic semiconductors are usually low (below 5 µW cm−1 K−2) as compared with classic brittle inorganic thermoelectric materials, which greatly limit the electrical output power for flexible thermoelectrics. Here, large plasticity and high power factor in bulk two‐dimensional van der Waals (2D vdW) single‐crystalline SnSe2 are reported. SnSe2 crystals exhibit large plastic strains at room temperature and they can be morphed into various shapes without cracking, which is well captured by the inherent large deformability factor. As a semiconductor, the electrical transport properties of SnSe2 can be readily tuned in a wide range by doping a tiny amount of halogen elements. A high power factor of 10.8 µW cm−1 K−2 at 375 K along the in‐plane direction is achieved in plastic single‐crystalline Br‐doped SnSe2, which is the highest value among the reported flexible inorganic and organic thermoelectric materials. Combining the good plasticity, excellent power factors, as well as low‐cost and nontoxic elements, bulk 2D vdW single‐crystalline SnSe2 shows great promise to achieve high power density for flexible thermoelectrics. [ABSTRACT FROM AUTHOR]

Doping of external elements can substantially optimize the carriers, modulate the electronic structure, or affect the phonon dynamics[4] and, thus, have a significant impact on the TE performance. MODULATION OF ELECTRICAL TRANSPORT Carrier concentration optimization has always been an efficient route to improve TE performance in solids. This special issue of I Applied Physics Letters i presents pioneering articles in the field of thermoelectric (TE) materials and devices. In this regard, Wang I et al. i have shown that the strong anharmonic phonon scattering through the Umklapp process and acoustic-optical phonon coupling causes very low I i SB lat sb in single crystalline Bi SB 2 sb O SB 2 sb Se and the maximum zT reaches ~0.188 at 390 K.[19] The van der Waals heterostructure of layered Bi SB 4 sb GeTe SB 7 sb also exhibits intrinsically ultra-low I i ~ 0.42 W m SP -1 sp K SP -1 sp at 380 K due to the presence of large anharmonicity in the lattice.[20] NEW THERMOELECTRIC MATERIALS The involvement of theoretical studies and predictions in materials have remarkably advanced this field of thermoelectrics. [Extracted from the article]

• Micro-mesoporous TS-1 was synthesized by adding NaOH. • Reasonable inference of oxidation mechanism of p -diethylbenzene. • Addition of Na into zeolite skeleton improves the selectivity of products. The micro-mesoporous TS-1 catalyst was synthesized by directly introducing NaOH during the synthesis of zeolite. As the first choice for many oxidation reactions, TS-1/H 2 O 2 catalytic system is an environmentally friendly reaction system. However, the number and mechanism of Ti active sites participating in the reaction in TS-1 zeolite are seldom studied so far. Using TS-1 zeolite with and without NaOH as catalyst, p -diethylbenzene (PDEB) was oxidized in batch reactor to prepare p -ethylacetophenone and 1-(4-ethylphenyl)-1-ethanol. Reaction conditions including solvent, additives, temperature, time, dosage and oxidant were explored. The optimum reaction conditions, the conversion of PDEB was 27.7 % and the total selectivity was 74.5 % over TS-1-NaOH zeolite catalyst, where the selectivity of p -ethylacetophenone and 4-ethyl-α-methylbenzyl alcohol was 33.4 % and 41.1 %, respectively. Introducing mesoporous structure reduces the mass transfer resistance of the reaction and improves the selectivity of the target product. Based on the free radical reaction mechanism and the oxidative decomposition process of H 2 O 2 , it is inferred that the oxidation mechanism of PDEB in H 2 O 2 system is a free radical reaction with the participation of •O 2 −. [Display omitted] [ABSTRACT FROM AUTHOR]

To explore the association between lipid profiles and left ventricular hypertrophy in a Chinese general population. We conducted a retrospective observational study to investigate the relationship between lipid markers [including triglycerides, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein (HDL) cholesterol, non-HDL-cholesterol, apolipoprotein A-I, apolipoprotein B, lipoprotein[a], and composite lipid profiles] and left ventricular hypertrophy. A total of 309,400 participants of two populations (one from Beijing and another from nationwide) who underwent physical examinations at different health management centers between 2009 and 2018 in China were included in the cross-sectional study. 7,475 participants who had multiple physical examinations and initially did not have left ventricular hypertrophy constituted a longitudinal cohort to analyze the association between lipid markers and the new-onset of left ventricular hypertrophy. Left ventricular hypertrophy was measured by echocardiography and defined as an end-diastolic thickness of the interventricular septum or left ventricle posterior wall > 11 mm. The Logistic regression model was used in the cross-sectional study. Cox model and Cox model with restricted cubic splines were used in the longitudinal cohort. In the cross-sectional study, for participants in the highest tertile of each lipid marker compared to the respective lowest, triglycerides [odds ratio (OR): 1.250, 95% CI : 1.060 to 1.474], HDL-cholesterol (OR: 0.780, 95% CI : 0.662 to 0.918), and lipoprotein(a) (OR : 1.311, 95% CI : 1.115 to 1.541) had an association with left ventricular hypertrophy. In the longitudinal cohort, for participants in the highest tertile of each lipid marker at the baseline compared to the respective lowest, triglycerides [hazard ratio (HR): 3.277, 95% CI : 1.720 to 6.244], HDL-cholesterol (HR : 0.516, 95% CI : 0.283 to 0.940), non-HDL-cholesterol (HR : 2.309, 95% CI : 1.296 to 4.112), apolipoprotein B (HR : 2.244, 95% CI : 1.251 to 4.032) showed an association with new-onset left ventricular hypertrophy. In the Cox model with forward stepwise selection, triglycerides were the only lipid markers entered into the final model. Lipids levels, especially triglycerides, are associated with left ventricular hypertrophy. Controlling triglycerides level potentiate to be a strategy in harnessing cardiac remodeling but deserve to be further investigated. [ABSTRACT FROM AUTHOR]

Metal halide perovskites (MHPs) hold great potential in thermoelectric (TE) applications, thanks to their regular and soft lattice in nature. However, the poor electrical conductivity caused by low charge carrier density (<1014 cm−3 for lead‐based MHPs) strongly impedes its TE development. In this scenario, tin halide perovskites (THPs) emerge as promising TE candidates owing to their high background hole densities (>1019 cm−3). However, further electrical doping remains challenging, originating from the limited capability of accommodating heterogeneous dopants and the heavy compensation in THPs. Herein, a novel diffusion‐mediated doping approach is demonstrated to prominently increase the p‐type doping level of THPs by a sequence of air exposure and 2,3,5,6‐tetrafluoro‐7,7,8,8‐tetracyanoquinodimethane (F4TCNQ) surface treatments. In paradigm photovoltaic THP materials—CH(NH2)2SnI3 (namely FASnI3), the electrical conductivity is dramatically increased by 300× from 0.06 to 18 S cm−1 in thin films, leading to a remarkable enhancement of power factor by 25× up to 53 μW m−1 K−2. In contrast, only a slight variation of thermal conductivity is observed after F4TCNQ deposition, which is in accordance with the increase in electrical conductivity, indicating that the lattice structures of FASnI3 remain intact after doping. This study paves an illuminating way to ameliorate TE properties in halide perovskites. [ABSTRACT FROM AUTHOR]

Thermoelectric (TE) power generation is expected to be one of the most effective solutions to convert industrial exhaust heat to electricity for conserving fossil energy and reducing carbon emissions. However, its real application is obstructed decisively by the weakness of the service stability of state‐of‐the‐art TE materials at high temperatures in air. Refractory iron silicide (β‐FeSi2) used to be widely investigated as TE materials, but the low zT has restricted its practical application and even made it almost vanish from TE research in recent years. Here, guided by theoretical calculation, ultrahigh solubility of Ir on the Fe sites of β‐FeSi2 is successfully realized. Doping 16% Ir elicits multi‐valley electrical conduction and phonon‐electron scattering, doubling the previous zT record of β‐FeSi2 to ≈0.6 at 1000 K. The TE properties of the obtained β‐FeSi2 are practically unchanged after thermal aging in air at 1173 K. The new conceptual electrode‐less β‐FeSi2‐based refractory module demonstrates considerable power density and stable power generation when it is burned by a gas flame in air. These results mark a step toward developing practical TE power generation technology for the recovery of industrial waste heat. [ABSTRACT FROM AUTHOR]

The utility of a solvent is one of the key factors that impacts resultant film morphology. However, the effect of solvent-dependent morphology on the doping process and electrical conductivity has not been adequately elucidated. In this work, we compared the morphology of chloroform- and chlorobenzene-processed thiophene polymer films and investigated how the choice of solvent influences film morphology, doping level, charge transport properties, and thus electrical conductivity. It was found that the film drop-casted from chloroform exhibits better crystallinity than that drop-casted from chlorobenzene. The crystallinity has negligible impact on the doping level but significant impact on charge transport properties. As a result, the chloroform-processed film shows a higher electrical conductivity of up to 408 S cm−1 due to a high carrier mobility related to the continuously crystalline domains in film. This finding indicates that the choice of solvent for preparation of film, which strongly correlated with molecular orientation, is a new strategy to optimize the electrical conductivity of doped polymers. [ABSTRACT FROM AUTHOR]

Etching characteristics of p-type (BiSb) 2 Te 3 films were studied with CH 4 /H 2 /Ar gas mixture using an inductively coupled plasma (ICP)-reactive ion etching (RIE) system. The effects of gas mixing ratio, working pressure and gas flow rate on the etch rate and the surface morphology were investigated. The vertical etched profile with the etch rate of 600 nm/min was achieved at the optimized processing parameters. X-ray photoelectron spectroscopy (XPS) analysis revealed the non-uniform etching of (BiSb) 2 Te 3 films due to disparate volatility of the etching products. Micro-masking effects caused by polymer deposition and Bi-rich residues resulted in roughly etched surfaces. Smooth surfaces can be obtained by optimizing the CH 4 /H 2 /Ar mixing ratio. [ABSTRACT FROM AUTHOR]

Chemical doping of donor–acceptor (D–A) polymers is essential for their usage in highly efficient optoelectronic devices. The crucial challenge remains to synergistically improve the carrier concentration and mobility of these polymers via a single solution doping method. Here, a D–A polymer, Pg32T‐OTz is designed and synthesized, containing a weak‐acceptor–strong‐donor backbone with nonpolar (alkoxy) and polar (ethylene glycol) side chains. Pure integer charge transfer (ICT) is shown to occur in 2,3,5,6‐tetrafluoro‐tetracyanoquinodimethane (F4TCNQ)‐doped D–A polymer at a low doping level. It is shown that the ordered edge‐on orientations of ICT structures overcome the Coulomb interactions and endow a long‐range hole delocalization, while few charge transfer complex states form in amorphous regions and bridge the crystalline ICT structures at high doping level, creating a network that sustains efficient charge transport. As a result, simultaneously high carrier concentration and high mobility are realized for F4TCNQ‐doped Pg32T‐OTz and thus a high electrical conductivity up to 550 S cm−1 is approached, which is the highest value among any doped polymers via a single‐solution doping process. This work demonstrates that the modulation of the acceptor strength combined with side‐chain engineering is an effective molecular design strategy to promote both the doping efficiency and carrier transport property of D–A polymers. [ABSTRACT FROM AUTHOR]

La3Te4-based rare-earth telluride is a kind of n-type high-temperature thermoelectric (TE) material with an operational temperature of up to 1273 K, which is a promising candidate for thermoelectric generators. In this work, the Sm substitution in La3−xSmxTe4/Ni composites is reported. The electrical transport property of La3−xSmxTe4 is modified by reducing carrier concentration due to the substitution of Sm2+ for La3+. The electric thermal conductivity decreases by 90% due to carrier concentration reduction, which mainly contributes to a reduction in total thermal conductivity. Lattice thermal conductivity also decreases by point-defect scattering by Sm doping. Meanwhile, based on our previous study, compositing nickel improves the thermal stability of the La3 − xSmxTe4 matrix. Finally, combined with carrier concentration optimization and the decreased thermal conductivity, a maximum zT of 1.1 at 1273 K and an average zTave value of 0.8 over 600 K–1273 K were achieved in La2.315Sm0.685Te4/10 vol.% Ni composite, which is among the highest TE performance reported in La3Te4 compounds. [ABSTRACT FROM AUTHOR]

Phosphomolybdic acid (HPMo) supported on microporous nanocrystalline titanium silicalite-1 zeolite (Nano-TS-1) catalysts were prepared in the absence or presence of hydrogen peroxide via the impregnation method. The catalysts were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), UV-visible diffuse reflectance spectroscopy (UV-vis), N2 adsorption–desorption, 31P and 29Si magic angle spinning nuclear magnetic resonance (MAS-NMR), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results of FT-IR, UV-vis and 31P MAS-NMR characterization confirm that the Keggin framework structure of the HPMo catalyst supported by the Nano-TS-1 is maintained, and a small amount of peroxomolybdatephosphate species is generated after the introduction of H2O2. The results of the kinetics research experiments show that the adsorption desulfurization activity of various aromatic sulfur-containing compounds over Nano-TS-1 and supported HPMo catalysts decreases in the order thiophene (TH) > benzothiophene (BT) > dibenzothiophene (DBT). Besides, the time to reach adsorption saturation is extended in turn, which is the result of their diffusion effect in microporous zeolites. The catalysts exhibit high catalytic activity in the oxidation of DBT and TH under mild conditions. Under selected conditions, i.e. m(oil)/m(catalyst) = 8.0 g/0.15 g, moL(O/S) = 10, V(model oil/ethanol) = 10.0 mL/10.0 mL, the desulfurization rates of TH and DBT are 99.8% and 58.6%, respectively. The results show that the supported HPMo or HPMo-H2O2 catalysts exhibit oxidative desulfurization efficiency in the order TH > DBT > BT, which may be attributed to the combined effect of the electron cloud density on the sulfur atoms, the pseudo liquid phase of HPMo and shape selectivity over Nano-TS-1. [ABSTRACT FROM AUTHOR]