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.

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.