Carbon coated LaFe_(0.92)Pd_(0.08)O_(3) composites for catalytic transfer hydrogenation:Balance in the ability of substrates adsorption and conversion

Catalytic transfer hydrogenation(CTH)is a green and efficient pathway for selective hydrogenation of unsaturated aldehydes and ketones.However,managing the abilities of solid catalysts to adsorb substrates and to convert them into desired products is a challenging task.Herein,we report the synthesis of carbon coated LaFe_(0.92)Pd_(0.08)O_(3) composites(LFPO-8@C)for CTH of benzaldehyde(BzH)into benzyl alcohol(BzOH),using isopropanol(IPA)as hydrogen source.The coating with carbon improves the ability to adsorb/transfer reactants from solution to active sites,and the doping of Pd2+at Fe3+site strengthens the ability of LaFeO_(3) to convert BzH into BzOH.A balanced point between them(i.e.,abilities to adsorb BzH and to convert BzH into BzOH)is obtained at LFPO-8@C,which exhibits a BzOH formation rate of 3.88 mmol·gcat^(-1)·h^(-1) at 180℃ for 3 h,which is 1.50 and 2.72 times faster than those of LFPO-8 and LaFeO_(3)@C.A reaction mechanism is proposed,in which the acidic sites(e.g.,Fe^(4+),oxygen vacancy)are used for the activation of C=O bond of BzH and O-H bond of IPA,and the basic sites(e.g.,lattice oxygen)for the activation ofα-H(O-H)bond of IPA.

Electrocatalytic synthesis of C-N coupling compounds from CO_(2) and nitrogenous species

The electrocatalytic synthesis of C-N coupling compounds from CO_(2) and nitrogenous species not only offers an effective avenue to achieve carbon neutral-ity and reduce environmental pollution,but also establishes a route to synthesize valuable chemicals,such as urea,amide,and amine.This innovative approach expands the application range and product categories beyond simple carbona-ceous species in electrocatalytic CO_(2) reduction,which is becoming a rapidly advancing field.This review summarizes the research progress in electrocatalytic urea synthesis,using N_(2),NO_(2)^(-),and NO_(3)^(-)as nitrogenous species,and explores emerging trends in the electrosynthesis of amide and amine from CO_(2) and nitro-gen species.Additionally,the future opportunities in this field are highlighted,including electrosynthesis of amino acids and other compounds containing C-N bonds,anodic C-N coupling reactions beyond water oxidation,and the catalytic mechanism of corresponding reactions.This critical review also captures the insights aimed at accelerating the development of electrochemical C-N coupling reactions,confirming the superiority of this electrochemical method over the traditional techniques.

Enhancing visible-light-driven NO oxidation through molecular‐level insights of dye-loaded sea sands

Natural minerals,abundant and easily obtained through simple physical processing,offer a cost-effective and environmentally friendly solution for dyeing wastewater disposal and air pollution treatment.This study investigates the photocatalytic removal of NO using natural different types of dyes,loaded on natural sand,under visible light illumination.By examining various coating concentrations of dyes and sand weights,we discovered that sand loaded with Rhodamine B(RhB)exhibits high activity for the photo-oxidation of NO.A combination results of X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),Fourier transform infrared spectroscopy(FTIR)and thermogravimetric(TG)analyses confirm the presence of SiO_(2),CaCO_(3),Al_(2)O_(3)and iron oxides as the main components of the sand.Furthermore,studying RhB-loaded individual components reveals that CaCO_(3)plays a crucial role in enhancing the NO removal rate.Experimental results and theoretical calculations demonstrate the establishment of a directional charge transfer channel from CaCO_(3)to RhB,facilitating the adsorption and activation of molecular NO and O_(2).This work not only promotes the utilization of natural mineral resources but also enriches the fields of environmental photochemistry and semiconductor photocatalysis.

双Ⅱ型SnO_(2)@ZnS-ZnSn(OH)_(6)异质结构建内部电场用于高效光催化NO氧化去除

精心设计的异质结光催化剂已经被证明能够有效地促进电荷转移,从而实现特定的迁移路径和长的载流子寿命,这在进一步提高性能方面具有巨大的潜力.然而,传统二元异质结光催化剂的光催化性能仍然受到其较低的载流子分离效率的影响.本文报道了一种通过原位面对面生长直接合成双Ⅱ型SnO_(2)@ZnS-ZHS(ZHS=ZnSn(OH)_(6))三元异质结的策略.基于可靠的实验和理论计算,揭示了双Ⅱ型SnO_(2)@ZnSZHS的载流子动力学提升机制.SnO_(2)的光生空穴(h+)能够分别迁移到ZHS和ZnS的价带,确保了SnO_(2)@ZnS-ZHS可以保持双氧化电位来产生足够的羟基自由基(·OH)参与NO氧化反应.这种独特的双Ⅱ型SnO_(2)@ZnS-ZHS三元结构在光照30 min后对NO去除率高达44.5%,活性分别是ZHS的23.5倍、SnO_(2)的29.7倍和ZnS的15.9倍.光催化活性提升与独特的双Ⅱ型反应机理反映了SnO_(2)@ZnS-ZHS异质结构的优势,本工作有望为三元异质结的设计提供可行的思路.

Catalytic combustion of volatile organic compounds using perovskite oxides catalysts—a review

With the rapid development of industry,volatile organic compounds(VOCs)are gaining attention as a class of pollutants that need to be eliminated due to their adverse effects on the environment and human health.Catalytic combustion is the most popular technology used for the removal of VOCs as it can be adapted to different organic emissions under mild conditions.This review first introduces the hazards of VOCs,their treatment technologies,and summarizes the treatment mechanism issues.Next,the characteristics and catalytic performance of perovskite oxides as catalysts for VOC removal are expounded,with a special focus on lattice distortions and surface defects caused by metal doping and surface modifications,and on the treatment of different VOCs.The challenges and the prospects regarding the design of perovskite oxides catalysts for the catalytic combustion of VOCs are also discussed.This review provides a reference base for improving the performance of perovskite catalysts to treat VOCs.

Rationally designed synthesis of bright AgInS2/ZnS quantum dots with emission control

In the blossoming field of Cd-free semiconductor quantum dots(QDs),ternary Ⅰ-Ⅲ-VI QDs have received increasing attention due to the ease of the environmentally friendly synthesis of high-quality materials in water,their high photoluminescence(PL)quantum yields(QYs)in the red and near infrared(NIR)region,and their inherently low toxicity.Moreover,their oxygen-insensitive long PL lifetimes of up to several hundreds of nanoseconds close a gap for applications exploiting the compound-specific parameter PL lifetime.To overcome the lack of reproducible synthetic methodologies and to enable a design-based control of their PL properties,we assessed and modelled the synthesis of high-quality MPA-capped AglnS2/ZnS(AlS/ZnS)QDs.Systematically refined parameters included reaction time,temperature,Ag:In ratio,S:In ratio,Zn:In ratio,MPA:ln ratio,and pH using a design-of-experiment approach.Guidance for the optimization was provided by mathematical models developed for the application-relevant PL parameters,maximum PL wavelength,QY,and PL lifetime as well as the elemental composition in terms of Ag:ln:Zn ratio.With these experimental data-based models,MPA:ln and Ag:ln ratios and pH values were identified as the most important synthesis parameters for PL control and an insight into the connection of these parameters could be gained.Subsequently,the experimental conditions to synthetize QDs with tunable emission and high QY were predicted.The excellent agreement between the predicted and experimentally found PL features confirmed the reliability of our methodology for the rational design of high quality AlS/ZnS QDs with defined PL features.This approach can be straightforwardly extended to other ternary and quaternary QDs and to doped QDs.

Improved dark ambient degradation of organic pollutants by cerium strontium cobalt perovskite

This work investigates the effect of cerium substation into strontium cobalt perovskites(CeSrCoO)for the oxidative degradation of OrangeⅡ(OII)in dark ambient conditions without the aid of any external stimulants such as light,heating or chemical additives.The OII degradation rate by CeSrCoO reached 65%in the first hour,whilst for the blank sample without cerium(SrCoO)took over 2 hr to reach the same level of OII degradation.Hence,the cerium substitution improved the catalytic activity of the perovskite material,mainly associated with the Ce0.1Sr0.9CoO3 perovskite phase.Upon contacting CeSrCoO,the-N=Nazo bonds of the OII molecules broke down resulting in electron donation and the formation of by-products.The electrons are injected into the CeSrCoO and resulted in a redox pair of Co3+/Co2+,establishing a bridge for the electron transfer between OII and the catalysts.Concomitantly,the electrons also formed reactive species(·OH)responsible for OII degradation as evidenced by radical trapping experiment.Reactive species were formed via the reaction between 02 and donated electrons from OII with the aid of cobalt redox pair.As the prepared materials dispensed with the need for light irradiation and additional oxidants,it opens a window of environmental applications for treating contaminated wastewaters.

Competition among rare earth elements on sorption onto six seaweeds

Sorption has been proposed as a promising approach towards a sustainable water decontamination and recently to the recycling of rare earth elements(REE).Although living seaweed have been shown to be capable of removing REE from contaminated solutions,no studies have yet compared the effects of REE competition on sorption onto different groups of seaweed.These effects were analysed in the present study by exposing six living seaweeds(Ulva lactuca,Ulva intestinalis,Fucus spiralis,Fucus vesiculosus,Gracilaria sp.and Osmundea pinnatifida)(3 g/L,fresh weight) to mono-element and multi-element solutions of Y,La,Ce,Pr,Nd,Eu,Gd,Tb and Dy(1 μmol/L).Results show a preference towards light REE in mono-element solutions,which is reduced when in competition with other REE.The competitive effect is less pronounced in heavy REE indicating that these are still able to bind to the macroalgae despite the presence of competing ions.Contrary to water content(%),seaweed specific surface area(cm^(2)/g) shows to be an important factor in the sorption of REE,since larger surface area is associated with higher removal and larger competitive effect.