Highly selective photocatalytic reduction of CO_(2) to CH_(4) on electron-rich Fe species cocatalyst under visible light irradiation

Efficient photocatalytic reduction of CO_(2) to high-calorific-value CH4,an ideal target product,is a blueprint for C_(1)industry relevance and carbon neutrality,but it also faces great challenges.Herein,we demonstrate unprecedented hybrid SiC photocatalysts modified by Fe-based cocatalyst,which are prepared via a facile impregnation-reduction method,featuring an optimized local electronic structure.It exhibits a superior photocatalytic carbon-based products yield of 30.0μmol g^(−1) h^(−1) and achieves a record CH_(4) selectivity of up to 94.3%,which highlights the effectiveness of electron-rich Fe cocatalyst for boosting photocatalytic performance and selectivity.Specifically,the synergistic effects of directional migration of photogenerated electrons and strongπ-back bonding on low-valence Fe effectively strengthen the adsorption and activation of reactants and intermediates in the CO_(2)→CH_(4) pathway.This study inspires an effective strategy for enhancing the multielectron reduction capacity of semiconductor photocatalysts with low-cost Fe instead of noble metals as cocatalysts.

Co_(3)S_(4)-pyrolysis lotus fiber flexible textile as a hybrid electrocatalyst for overall water splitting

Electrocatalytic overall water splitting(OWS),a pivotal approach in addressing the global energy crisis,aims to produce hydrogen and oxygen.However,most of the catalysts in powder form are adhesively bounding to the electrodes,resulting in catalyst detachment by bubble generation and other uncertain interference,and eventually reducing the OWS performance.To surmount this challenge,we synthesized a hybrid material of Co_(3)S_(4)-pyrolysis lotus fiber(labeled as Co_(3)S_(4)-p LF)textile by hydrothermal and hightemperature pyrolysis processes for electrocatalytic OWS.Owing to the natural LF textile exposing the uniformly distributed functional groups(AOH,ANH_(2),etc.)to anchor Co_(3)S_(4)nanoparticles with hierarchical porous structure and outstanding hydrophily,the hybrid Co_(3)S_(4)-p LF catalyst shows low overpotentials at 10 m A cm^(-2)(η_(10,HER)=100 m Vη_(10,OER)=240 mV)alongside prolonged operational stability during electrocatalytic reactions.Theoretical calculations reveal that the electron transfer from p LF to Co_(3)S_(4)in the hybrid Co_(3)S_(4)-p LF is beneficial to the electrocatalytic process.This work will shed light on the development of nature-inspired carbon-based materials in hybrid electrocatalysts for OWS.

Sodium dodecyl sulfate-decorated MOF-derived porous Fe2O3 nanoparticles: High performance, recyclable photocatalysts for fuel denitrification

Magnetically recyclable porous sodium dodecyl sulfate(SDS)/Fe2O3 hybrids,which combine the porous structure of Fe2O3 and hydrophobicity of SDS,have been successfully synthesized for the first time.Porous Fe2O3 has been first pyrolyzed from MIL-100(Fe)using a simple two-step calcination route.Then,the obtained porous Fe2O3 nanoparticles have been self-assembled with SDS molecules and yielded hydrophobic SDS/Fe2O3 hybrids.The porous SDS/Fe2O3 hybrids have been demonstrated to be highly efficient for the denitrification of pyridine under visible light irradiation.The pyridine removal ratio has reached values as high as 100%after irradiation for 240 min.Combining the results of a series of experimental measurements,it was concluded that the superior photocatalytic performance of SDS/Fe2O3 hybrids could be attributed to(i)the fast electron transport owing to the unique porous structure of Fe2O3,(ii)the superior visible light absorption of Fe2O3 nanoparticles,and(iii)the“bridge molecule”role of SDS efficiently improving the separation and transfer across the interfacial domain of SDS/Fe2O3 of photogenerated electron-hole pairs.More significantly,after the catalytic reaction,the SDS/Fe2O3 hybrids could be easily recovered using magnets and reused during subsequent cycles,which indicated their stability and recyclability.

细鳞鲑F2池塘养殖生长特性研究

为探索养殖环境条件下细鳞鲑(Brachymystax lenok) 的生长特性,2016年3月28日至5月22日对养殖在自然水温(10℃~12℃)的1龄幼鱼进行了研究,测量幼体全长与体重,并用计算机软件SPSS和Excel对获得的数据进行处理分析。研究结果显示:在试验条件下,细鳞鲑全长和体重的瞬时生长率、全长和体重的日增长量,全长和体重的相对增长率,都呈升高–降低–升高–降低–升高的变化趋势,最高峰值出现在383日龄。细鳞鲑体重与日龄的关系为W = 0.4392e0.0121t (R2 = 0.9757);全长与日龄的方程式为L = 4.4785e0.0035t (R2 = 0.9913);体重与全长的方程式为W = 0.0027L3.4106(R2 = 0.9776),其中异速生长系数b >3,表明细鳞鲑1龄幼鱼为异速生长类型,体重的生长快于全长生长。

Coating of Medical-Grade PVC Material with ZnO for Antibacterial Application

The ZnO sol well-crystallized was prepared by the sol-gel method. The ZnO films were coated on medical-grade PVC surface by the improved organic-inorganic interfacial adhesion method. The physical and photocatalytic properties of the samples were characterized by XRD, SEM, DRS spectra and measured by the photodegradation reaction of Rho-damine B (RhB) and anti-bacteria for Escherichia coli (E. coli), respectively. The results show that pretreatment of PVC by the mix solution of THF-PVC helps to improve the amount and adhesion strength of ZnO suspension to PVC surface. The photocatalytic and antibacterial properties of the THF-ZnO/PVC film are better than that of the ZnO/PVC and neat PVC. Under UV irradiation, the THF-ZnO/PVC film shows the best antibacterial properties with 99% kill rate of bacteria.

Theoretical investigation of the doping effect on interface storage in the graphene/silicene heterostructure as the anode for lithium-ion batteries

Van der Waals heterostructures made up of different two-dimensional(2D)materials have garnered consider-able attention as anodes for lithium-ion batteries(LIBs),and doping can significantly influence their electronic structures and lithium diffusion barriers.In this work,the effects of heteroatom(X=N,O,P,and S)doping in the graphene of the graphene/silicene(G/Si)heterostructure are comprehensively examined by using first-principles calculations.The stacking stability and mechanical stiffness of G/Si and doped G/Si(XG/Si)exhibit that N-doping can improve the structural stability of G/Si,thereby ensuring good cycling performance.The densities of states reveal that the dopants(N,O,and S)can greatly increase the electronic conductivity of G/Si.Importantly,the adsorption and diffusion behaviors of Li are primarily affected by the dopant and the doping site,resulting in ultrafast Li diffusivity.Therefore,N-doped G/Si at doping site 1(S1)shows a good and balanced property,which exhibits high potential to enhance the electrical performance of G/Si materials and offers a reference for selecting dopants in other 2D anode materials for LIBs.

Tuning electronic properties of cobalt phthalocyanines for oxygen reduction and evolution reactions

Metal–phthalocyanines are a class of catalytically active materials promising in energy conversion and storage fields(e.g.,electrocatalysis).However,understanding and controlling the electrochemical properties in metal-phthalocyanine systems is challenging.Herein,we elucidate the electrocatalytic origins of a series of cobalt-phthalocyanine molecular catalysts and finetune their electronic properties at the atomic level,both experimentally and computationally.The interactions between the cobalt center and the local coordination environment are regulated by introducing either electron-donating or electron-withdrawing groups on the phthalocyanine ligand,and the spin-orbit splitting of cobalt is increased by~0.15 eV compared with the nonsubstituted ligand.Specifically,the aminated cobalt phthalocyanine-based electrocatalysts exhibit low free energies in the ratedetermining steps of the oxygen reduction(-1.68 eV)and oxygen evolution reactions(0.37 eV).This contributes to the high electrocatalytic activity(e.g.,a halfwave potential of 0.84 V and an overpotential of 0.30 V at 10 mAcm^(-2)),featuring a high selectivity of a four-electron pathway(i.e.,a negligible by-product of hydrogen peroxide).These catalysts also exhibit exceptional kinetic current density(Tafel slope of 100 mV dec^(-1))in oxygen reduction reactions,in addition to a superior power density(158 mWcm^(-2))and a high cycling stability(>1,300 cycles)in Zn-air batteries,outperforming the commercial Pt/C and/or RuO2counterparts.

Cd3(C3N3S3)2 coordination polymer/graphene nanoarchitectures for enhanced photocatalytic H2O2 production under visible light

For a long time, there has been global concern over the environment and energy problems. Recently, the problems, which have brought about serious effect on the global living condition, have been in the ‘‘spotlight" and given impetus to the universal's efforts to head for the same direction: stem the worst warming and strive for the renewable energy source. Hydrogen peroxide(H_2O_2) is undoubtedly a good choice,which holds the promise as a clean, efficient, safe and transferrable energy carrier. Octahedral coordination polymer, Cd_3(C_3N_3S_3)_2, was found to be a robust photocatalyst for H_2O_2 generation under visible light irradiation. To further improve the H_2O_2 generation efficiency, adhering the octahedron to reduced graphene(rGO) was applied as the strategy herein. The study shows that by adhering Cd_3(C_3N_3S_3)_2to rGO, the formation of H_2O_2 is 2.5-fold enhanced and its deformation is concurrently suppressed. This work not only demonstrates the effectiveness of adhering Cd_3(C_3N_3S_3)_2polymer to rGO for the improvement of the polymer's photocatalytic performance, but also proposes a general way for the fabrication of graphene/coordination compound hybrids for maximizing their synergy.

Self-assembly synthesis of LAPO4 hierarchical hollow spheres with enhanced photocatalytic CO2-reduction performance

Urchin-like LaPO4 hollow spheres were successfully synthesized by a facile solution route using citric acid （CA） as a structure-directing agent. The size of the three-dimensional （3D） hollow spheres was tuned by changing the concentration of CA. The formation mechanism of the 3D LaPO4 hollow spheres was revealed by studying the time-dependent morphology evolution process. Importantly, compared with monodispersed one-dimensional （1D） LaPO4 nanorods, the 3D LaPO4 hollow spheres self-assembled from nanorods showed a 6.8-fold enhancement in photocatalytic activity for CO2 reduction, which is attributed to the synergistic effect of their hierarchical hollow structure, higher light-harvesting capacity, and faster electron transfer. Our findings provide not only a simple, facile method for the synthesis of hierarchical hollow micro/nanoarchitectures but also an efficient route for enhancing the photocatalytic performance.

Solar photocatalytic energy conversion

Development of clean and renewable energy sources is an inevitable choice of human society to address the energy shortage and environmental deterioration problems nowadays.Hydrogen has been recognized as the most ideal and clean fuel because its burning product is water without second pollution.Hydrogen is

Heterojunction： important strategy for constructing composite photocatalysts

As an ideal solution to energy and environment issues,conversion of sunlight into solar fuels by photocatalytic water splitting and greenhouse gas(CO_2)reduction has attracted keen research interest of multi-field scientists.In the past four decades,a large number of semiconductor photocatalysts have been

Neuron-inspired design of hierarchically porous carbon networks embedded with single-iron sites for efficient oxygen reduction

The rational structure design and active-site regulation of catalysts is crucial for high energy output. Herein, B, F co-doped Fe–N–C embedded in a flexible and free-standing hierarchical porous carbon framework(Fe–SA–FPCS) was reported. Owing to the synergism of optimized intrinsic activity, fast mass transfer and well exposed active sites, the Fe–SA–FPCS exhibits a high halfwave potential(E1/2=0.89 V vs. RHE) and small Tafel slope(66 m V dec^(-1)). Theoretical calculations uncover that B, F co-doping could accelerate the desorption of OH* on Fe sites, which can effectively increase oxygen reduction reaction activity. As the cathode for Zn–air batteries(ZABs), Fe–SA–FPCS demonstrates a high open-circuit voltage(1.51 V), large peak power density(168.4 m W cm^(-2)) and excellent stability. The assembled flexible solid-state ZAB exhibits excellent stability during charge and discharge cycling in the flat/bent state, and is promising for the application of portable and flexible devices. This work provides a new perspective for the fabrication of single-atom electrocatalysts with well-designed structure and excellent electrochemical energy conversion and storage capability.