Selectivity control of photocatalytic CO_(2) reduction over ZnS-based nanocrystals:A comparison study on the role of ionic cocatalysts

Taking copper doped ZnS(ZnS:Cu)nanocrystals as the main body of photocatalyst,the influence of different base transition metal ions(M^(2+)=Ni^(2+),Co^(2+),Fe^(2+)and Cd^(2+))on photocatalytic CO_(2)reduction in inorganic reaction system is investigated.Confined single-atom Ni^(2+),Co^(2+),and Cd^(2+)sites were created via cation-exchange process and enhanced CO_(2)reduction,while Fe^(2+)suppressed the photocatalytic activity for both water and CO_(2)reduction.The modified ZnS:Cu photocatalysts(M/ZnS:Cu)demonstrated tunable product selectivity,with Ni^(2+)and Co^(2+)showing high selectivity for syngas production and Cd^(2+)displaying remarkable formate selectivity.DFT calculations indicated favorable H adsorption free energy on Ni^(2+)and Co^(2+)sites,promoting the hydrogen evolution reaction.The selectivity of CO_(2)reduction products was found to be sensitive to the initial intermediate adsorption states.*COOH formed on Ni^(2+)and Co^(2+)while*OCHO formed on Cd^(2+),favoring the production of CO and HCOOH as the main products,respectively.This work provides valuable insights for developing efficient solar-to-fuel platforms with controlled CO_(2)reduction selectivity.

Nonequilibrium molecular dynamics for accelerated computation of ion–ion correlated conductivity beyond Nernst–Einstein limitation

Condensed matters with high ionic conductivities are crucial in various solid devices such as solid-state batteries. The conduction ischaracterized by the cooperative ionic motion associated with the high carrier density. However, the high cost of computingcorrelated ionic conductivities has forced almost all ab initio molecular dynamics (MD) to rely on the Nernst–Einstein dilute-solutionapproximation, which ignores the cross-correlation effect. Here we develop a chemical color-diffusion nonequilibrium MD (CCD-NEMD) method, which enables to calculate the correlated conductivities with fewer sampling steps than the conventional MD. ThisCCD-NEMD is demonstrated to well evaluate the conductivities in the representative solid electrolyte bulk Li10GeP2S12 andLi_(7)La_(3)Zr_(2)O_(12). We also applied CCD-NEMD to the grain boundary of Li_(7)La_(3)Zr_(2)O_(12) and demonstrated its applicability for calculatinginterfacial local conductivities, which is essential for investigating grain boundaries and composite electrolytes. CCD-NEMD canprovide further accurate understanding of ionics with ionic correlations and promote developing solid devices.

Stabilizing layered superlattice MoSe_(2)anodes by the rational solvation structure design for low-temperature aqueous zinc-ion batteries

Aqueous zinc-ion batteries(AZIBs)have attracted widespread attention due to their intrinsic merits of low cost and high safety.However,the poor thermodynamic stability of Zn metal in aqueous electrolytes inevitably cause Zn dendrites growth and interface parasitic side reactions,resulting in unsatisfactory cycling stability and low Zn utilization.Replacing Zn anode with intercalation-type anodes have emerged as a promising alternative strategy to overcome the above issues but the lack of appropriate anode materials is becoming the bottleneck.Herein,the interlayer structure of MoSe_(2)anode is preintercalated with long-chain polyvinyl pyrrolidone(PVP),constructing a periodically stacked p-MoSe_(2)superlattice to activate the reversible Zn^(2+)storage performance(203 mAh g^(−1)at 0.2 A g^(−1)).To further improve the stability of the superlattice structure during cycling,the electrolyte is also rationally designed by adding 1,4-Butyrolactone(γ-GBL)additive into 3 M Zn(CF_(3)SO_(3))_(2),in whichγ-GBL replaces the H2O in Zn^(2+)solvation sheath.The preferential solvation ofγ-GBL with Zn^(2+)effectively reduces the water activity and helps to achieve an ultra-long lifespan of 12,000 cycles for p-MoSe_(2).More importantly,the reconstructed solvation structure enables the operation of p-MoSe_(2)||ZnxNVPF(Na3V2(PO4)2O_(2)F)AZIBs at an ultra-low temperature of−40°C,which is expected to promote the practical applications of AZIBs.

Efficient and stable tin-based perovskite solar cells by introducing π-conjugated Lewis base

Tin-based perovskite solar cells(TPSCs)as the most promising candidate for lead-free PSCs have incurred extensive researches all over the world.However,the crystallization process of tin-based perovskite is too fast during the solution-deposited process,resulting in abundant pinholes and poor homogeneity that cause serious charge recombination in perovskite layer.Here,we employed theπ-conjugated Lewis base molecules with high electron density to systematically control the crystallization rate of FASnI3 perovskite by forming stable intermediate phase with the Sn-I frameworks,leading to a compact and uniform perovskite film with large increase in the carrier lifetime.Meanwhile,the introduction of theπ-conjugated systems also retards the permeation of moisture into perovskite crystal,which significantly suppresses the film degradation in air.These benefits contributed to a stabilizing power conversion efficiency(PCE)of 10.1%for the TPSCs and maintained over 90%of its initial PCE after 1000-h light soaking in air.Also,a steady-state efficiency of 9.2%was certified at the accredited test center.

Nanometer-size Na cluster formation in micropore of hard carbon as origin of higher-capacity Na-ion battery

Development of high-energy-density anode is crucial for practical application of Na-ion battery as a post Li-ion battery.Hard carbon(HC),though a promising anode candidate,still has bottlenecks of insufficient capacity and unclear microscopic picture.Usage of the micropore has been recently discussed,however,the underlying sodiation mechanism is still controversial.Herein we examined the origin for the high-capacity sodiation of HC,based on density functional theory calculations.We demonstrated that nanometersize Na cluster with 3–6 layers is energetically stable between two sheets of graphene,a model micropore,in addition to the adsorption and intercalation mechanisms.The finding well explains the extended capacity over typical 300 mAhg^(−1),up to 478 mAhg^(−1) recently found in the MgO-templated HC.We also clarified that the MgO-template can produce suitable nanometersize micropores with slightly defective graphitic domains in HC.The present study considerably promotes the atomistic theory of sodiation mechanism and complicated HC science.

Structure search of two-dimensional systems using CALYPSO methodology

The dimensionality of structures allows materials to be classified into zero-, one-, two-, and threedimensional systems. Two-dimensional (2D) systems have attracted a great deal of attention andtypically include surfaces, interfaces, and layered materials. Due to their varied properties, 2D systemshold promise for applications such as electronics, optoelectronics, magnetronics, and valleytronics.The design of 2D systems is an area of intensive research because of the rapid development of abinitio structure-searching methods. In this paper, we highlight recent research progress on acceleratingthe design of 2D systems using the CALYPSO methodology. Challenges and perspectives for futuredevelopments in 2D structure prediction methods are also presented.

二维有机-无机杂化钙钛矿:从材料性能到器件应用（英文）

二维(2D)钙钛矿材料(包括纯2D和准2D)是在传统意义上的三维钙钛矿晶格中插入大基团卤化铵形成的.在过去的20年里,二维钙钛矿材料种类不断丰富,相关理论研究不断深入,在光电器件领域的应用不断拓展.本综述介绍了2D钙钛矿材料的基本形成机制和性能,汇总和比较了2D钙钛矿薄膜的制备方法,并给出了其在太阳电池以及发光二极管领域的应用实例.最后,提出了该领域亟待解决的问题,以及未来的研究趋势.