Chalcogen-dependent catalytic properties of RuX2 (X = S/Se/Te) nanoparticles decorated carbon nanofibers for hydrogen evolution in acidic and alkaline media

Transition metal dichalcogenides(TMDs),with the general formula MX_(2)(M=Mo/W/Fe/Co/Ni,etc.;X=S/Se/Te),have attracted extensive research interests for hydrogen evolution reaction(HER).Compared with numerous studies on noble-metal-free TMDs,the chalcogen-dependent HER catalytic properties of noble-metal-based TMDs are lack of sufficient research attention.Herein,a facile electrospinning-assisted synthetic strategy is proposed to synthesize ruthenium dichalcogenides(RuX_(2),X=S/Se/Te)nanoparticles decorated carbon nanofibers(CNFs).Benefiting from the identical nanofibrous morphology and exposed crystal planes of RuX_(2)(111),the catalytic activities of RuX_(2)@CNFs samples were investigated and compared in a fair and direct manner.Detailed electrochemical measurements coupled with density functional theory calculations were carried out to probe their intrinsic HER catalytic activities,resulting in the catalytic activity order of RuS_(2)@CNFs>RuSe_(2)@CNFs>RuTe_(2)@CNFs in acidic media and that of RuS_(2)@CNFs>RuTe_(2)@CNFs>RuSe_(2)@CNFs in alkaline media.The superior catalytic performance of RuS_(2)@CNFs mainly stems from the relative lower HER energy barriers and thereby the higher intrinsic catalytic activity of RuS_(2)(111),leading to ultralow overpotentials of 44 and 9 mV at 10 mA·cm^(-2) in acidic and alkaline media,respectively.RuSe_(2)(111)is endowed with the more optimized Gibbs free energy of hydrogen adsorption(ΔGH*)than RuTe_(2)(111),but RuTe_(2)(111)shows enhanced catalytic property for H_(2)O dissociation and OH-desorption than RuSe_(2)(111),therefore,resulting in the altered catalytic activity sequences for RuSe_(2) and RuTe_(2) in acidic and alkaline media.

Can perfluorooctanoic acid be effectively degraded usingβ-PbO_(2)reactive electrochemical membrane?

Aqueous perfluorooctanoic acid(PFOA)elimination has raised significant concerns due to its persistence and bioaccumulation.Althoughβ-PbO_(2)plate anodes have shown efficient mineralization of PFOA,it remains unclear whether PFOA can be effectively degraded usingβ-PbO_(2)reactive electrochemical membrane(REM).Herein,we assessed the performance of Ti/SnO_(2)-Sb/La-PbO_(2)REM for PFOA removal and proposed a possible degradation mechanism.At a current density of 10 mA/cm2and a membrane flux of 8500(liters per square meter per hour,LMH),the degradation efficiency of 10 mg/L PFOA was merely8.8%,whereas the degradation efficiency of 0.1 mg/L PFOA increased to 96.6%.Although the porous structure of theβ-PbO_(2)REM provided numerous electroactive sites for PFOA,the generated oxygen bubbles in the pores could block the pore channels and adsorb PFOA molecules.These hindered the protonation process and significantly impeded the degradation of high-concentration PFOA.Quenching experiments indicated that·OH played dominant role in PFOA degradation.The electrical energy per order to remove 0.1 mg/L PFOA was merely 0.74 Wh/L,which was almost an order of magnitude lower than that of other anode materials.This study presents fresh opportunities for the electrochemical degradation of low-concentration PFOA usingβ-PbO_(2)REM.

Degradation and detoxification mechanisms of organophosphorus flame retardant tris(1,3-dichloro-2-propyl)phosphate(TDCPP)during electrochemical oxidation process

Electrochemical oxidation of aqueous tris(1,3-dichloro-2-propyl)phosphate(TDCPP)by using Ti/SnO_(2)-Sb/La-PbO_(2)as anode was investigated for the first time,and the degradation mechanisms and toxicity changes of the degradation intermediates were further determined.Results suggested that electrochemical degradation of TDCPP followed pseudo-first-order kinetics,and the reaction rate constant(k)was 0.0332 min^(−1)at the applied current density of 10 mA/cm^(2)and Na_(2)SO_(4)concentration of 10 mmol/L.There was better TDCPP degradation performance at higher current density.Free hydroxy radical(•OH)was proved to play dominant role in TDCPP oxidation via quenching experiment,with a relative contribution rate of 60.1%.A total of five intermediates(M1,C_(6)H_(11)Cl_(4)O_(4)P;M2,C_(3)H_(7)Cl_(2)O_(4)P;M3,C_(9)H_(16)Cl_(5)O_(5)P;M4,C_(9)H_(14)Cl_(5)O_(6)P;M5,C_(6)H_(10)Cl_(3)O_(6)P)were identified,and the intermediates were further degraded prolonging with the reaction time.Flow cytometer results suggested that the toxicity of TDCPP and degradation intermediates significantly reduced,and the detoxification efficiency was achieved at 78.1%at 180 min.ECOSAR predictive model was used to assess the relative toxicity of TDCPP and the degradation intermediates.The EC_(50)to green algae was 3.59 mg/L for TDCPP,and the values raised to 84,574,54.6,391,and 8920 mg/L for M1,M2,M3,M4,and M5,respectively,indicating that the degradation intermediates are less toxic or not toxic.Electrochemical advanced oxidation process is a valid technology to degrade TDCPP and pose a good detoxification effect.

Node line semimetal states in tungsten-based materials

Node line semimetals(NLSMs) were characterized by one-dimensional band crossings in their bulk electronic structures.The nontrivial band topology of NLSM gives rise to "drumhead" surface electronic excitations that exhibits exotic physical properties.The symmetries of crystalline provide the needed protection of node line from being gapped out by the perturbations that preserve the symmetry.The progress of NLSM in tungsten-based materials is reviewed with an emphasis on their symmetry-based protection,characteristic electronic band structures and their response to the spin-orbit coupling(SOC)and breaking of time-reversal symmetry.The potential exploration directions of tungsten-based NLSM in the future are also discussed.

厄他培南预防直肠癌高危手术部位感染的临床疗效分析

目的探讨厄他培南预防直肠癌术后手术部位感染的临床疗效及其影响因素分析。方法选取2010年3月到2022年3月在福建医科大学附属协和医院结直肠外科术前应用抗生素预防手术部位感染的直肠癌患者775例;通过倾向性评分匹配(PSM)后,共纳入230例术前应用抗生素预防手术部位感染的直肠癌患者,厄他培南组46例、非厄他培南组184例,对比厄他培南组和非厄他培南组预防直肠癌手术部位感染的疗效;采用Logistic回归单、多因素分析直肠癌手术部位感染的危险因素。结果厄他培南组患者表浅手术部位感染发生率低于非厄他培南组(8.7%vs.22.3%,P=0.038);单因素分析发现厄他培南(OR=4.317,P=0.038)、手术方式(P=0.0001)、肿瘤距离肛缘的距离(OR=0.718,P=0.011)、手术时间(OR=1.010,P=0.002)与直肠癌术后表浅手术部位感染密切相关;多因素分析结果表明:非厄他培南(OR=4.392,95%CI:1.325~14.564;P=0.016)、手术方式(APR手术,OR=25.65,95%CI:2.960~222.37;P=0.003)、手术时间(OR=1.011,95%CI:0.003~1.019;P=0.004)是直肠癌术后表浅手术部位感染的独立危险因素。结论厄他培南比非厄他培南组更有效预防直肠癌表浅手术部位感染,APR手术和手术时间长的直肠癌患者应积极应用厄他培南预防手术部位感染。

Temperature-controlled synthesis of heterostructured Ru-Ru_(2)P nanoparticles embedded in carbon nanofibers for highly efficient hydrogen production

Developing highly efficient,cost-effective,and stable electrocatalysts for hydrogen evolution reaction(HER)is of considerable importance but remains challenging.Herein,we report the fabrication of a robust Ru-based electrocatalyst,which comprises heterostructured Ru-Ru_(2)P nanoparticles that are embedded in the N,P-codoped carbon nanofibers(CNFs),through a synthetic strategy involving electrospinning and temperature-controlled pyrolysis treatment.The as-prepared Ru-Ru_(2)P catalyst(Ru-Ru_(2)P@CNFs)shows excellent HER catalytic activities with low overpotentials of 11 and 14 mV in acidic and alkaline media,respectively,to achieve a current density of 10 mA cm^(−2),which are superior to the individual components of pure Ru and Ru_(2)P catalysts.Density functional theory calculations demonstrate the existence of electronic coupling effect between Ru and Ru_(2)P at the heterointerfaces,leading to a well-modulated electronic structure with optimized hydrogen adsorption strength and enhanced electrical conductivity for efficient HER electrocatalysis.In addition,the overall synthetic strategy can be generalized for the synthesis of a series of transitional metal phosphide-based nanofibers,thereby holding a remarkable capacity for various potential applications.

Computational functionality-driven design of semiconductors for optoelectronic applications

The rapid development of the semiconductor industry has motivated researchers passion for accelerating the discovery of advanced optoelectronic materials.Computational functionality-driven design is an emerging branch of material science that has become effective at making material predictions.By combining advanced solid-state knowledge and high-throughput firstprinciples computational approaches with intelligent algorithms plus database development,experts can now efficiently explore many novel materials by taking advantage of the power of supercomputer architectures.Here,we discuss a set of typical design strategies that can be used to accelerate inorganic optoelectronic materials discovery from computer simulations:In silico computational screening;knowledge-based inverse design;and algorithm-based searching.A few representative examples in optoelectronic materials design are discussed to illustrate these computational functionality-driven modalities.Challenges and prospects for the computational functionality-driven design of materials are further highlighted at the end of the review.