Editorial for special issue on renewable energy conversion,utilization and storage

1.Foreword In light of the rapid depletion of fossil energy resources and the escalating environmental pollution crisis,there has been a significant surge in research focused on the development of technologies and materials for renewable energy conversion,utilization,and storage.This research area has gained paramount importance in addressing the pressing challenges of our time.

Synthesis of MoX2 (X =Se or S) monolayers with high-concentration 1T'phase on 4H/fcc-Au nanorods for hydrogen evolution

Controlled synthesis of transition metal dichalcogenide (TMD) monolayers with unusual crystal phases has attracted increasing attention due to their promising applications in electrocatalysis.However,the facile and large-scale preparation of TMD monolayers with high-concentration unusual crystal phase still remains a challenge.Herein,we report the synthesis of MoX2 (X =Se or S) monolayers with high-concentration semimetallic 1T'phase by using the 4H/face-centered cubic (fcc)-Au nanorod as template to form the 4H/fcc-Au@MoX2 nanocomposite.The concentrations of 1T'phase in the prepared MoSe2 and MoS2 monolayers are up to 86% and 81%,respectively.As a proof-of-concept application,the obtained Au@MoS2 nanocomposite is used for the electrocatalytic hydrogen evolution reaction (HER) in acid medium,exhibiting excellent performance with a low overpotential of 178 mV at the current density of 10 mNcm^2,a small Tafel slope of 43.3 mV/dec,and excellent HER stability.This work paves a way for direct synthesis of TMD monolayers with high-concentration of unusual crystal phase for the electrocatalytic application.

Two-dimensional Cu-porphyrin nanosheet membranes for nanofiltration

A kind of two-dimensional(2D)metal-organic framework(MOF)material,Cu-meso-tetrakis(4-carboxyphenyl)porphine(Cu-TCPP)nanosheets with wrinkled and flat morphologies are used as building blocks to assemble membranes by vacuum filtration(VF)and electrophoretic deposition(EPD)as energy-efficient nanofiltration(NF)membranes to remove dyes from water.Since the nanosheets with wrinkled structure can provide additional water transport channels,thereby increasing the water permeance,in the premise of a high rejection(>97.0%)for the dye brilliant blue G(BBG)(1.60 nm×1.90 nm),the water permeance of the membrane assembled by the wrinkled nanosheets(~1170 nm)is about 4 times that of the membrane assembled by the flat nanosheets(~530 nm),reaching 16.39 L·m^(−2)·h^(−1)·bar^(−1).Additionally,the use of the relatively flat nanosheets and the membrane preparation method of electrophoretic deposition is more conducive to stack nanosheets orderly and reduce defects.Therefore,the water permeance of the membrane prepared by EPD(~1170 nm)with flat nanosheets is about twice that of the membrane prepared by VF(~530 nm),achieving 9.40 L·m^(−2)·h^(−1)·bar^(−1)with similar rejection(>97.0%)of dye evans blue(EB)(3.10 nm×1.20 nm).Furthermore,these membranes still exhibit good separation performance at high pressure of 0.6 MPa.Nanosheets with diverse structures and various membrane fabrication processes provide new directions for the separation performance optimization of 2D MOF materials for water purification.

Recent advances of Rh-based intermetallic nanomaterials for catalytic applications

Rhodium(Rh)has received widespread attention in fundamental catalytic research and numerous industrial catalytic applications.Compared to homogeneous catalysts,Rh-based nanomaterials as heterogeneous catalysts are much easier to separate and collect after usage,making them more suitable for commercial use.To this purpose,there has been a constant demand in constructing stable and highly active Rh-based nanomaterials.In contrast to Rh-based solid solutions with a random distribution of metallic atoms in the lattice,Rh-based intermetallic compounds(IMCs)with a fixed stoichiometric ratio and an ordered atomic arrangement can ensure the homogenous distribution of active sites and structural stability in the catalytic process.In this review,we concentrate on the fabrication of Rh-based IMCs for catalytic applications.Various synthetic methods and protocols for the controlled preparation of Rh-based IMC are illustrated.Meanwhile,the catalytic applications and corresponding catalytic mechanisms are discussed.In addition,personal perspectives about the remaining challenges and prospects in this field are provided.We believe this review will be useful in directing the development of Rh-based IMC catalysts for heterogeneous catalysis.

Crystal facet-dependent electrocatalytic performance of metallic Cu in CO_(2)reduction reactions

Developing high-performance electrocatalysts for CO_(2) reduction reaction(CO_(2)RR)is crucial since it is beneficial for environmental protection and the resulting value-add chemical products can act as an alternative to fossil feedstocks.Nonetheless,the direct reduction of CO_(2) into long-chain hydrocarbons and oxygenated hydrocarbons with high selectivity remains challenging.Copper(Cu)shows a distinctive advantage that it is the only pure metal catalyst for reducing CO_(2) into multi-carbon(C_(2+))products and the certain facets(e.g.,(100),(111),(111))of Cu nanocrystals exhibit relatively low energy barriers for the formation of specific products(e.g.,CO,HCOOH,CH_(4),C_(2)H_(4),C_(2)H_(5)OH,and other C_(2+) products).Therefore,extensive studies have been carried out to explore the relationship between the facets of Cu nanocrystals and corresponding catalytic products.In this review,we will discuss the crystal facet-dependent electrocatalytic CO_(2)RR performance in metallic Cu catalysts,meanwhile,the detailed reaction mechanisms will be systematically summarized.In addition,we will provide a personal perspective for the future research directions in this emerging field.We believe this review is helpful to guide the design of high-selectivity Cu-based electrocatalysts for CO_(2)RR.

Graded interface engineering of 3D/2D halide perovskite solar cells through ultrathin(PEA)_(2)PbI_(4) nanosheets

2D halide perovskites have emerged as promising materials because of their stability and passivation effect in perovskite solar cells(PSCs).However,the introduction of bulky organic ammonium cations from 2D halide perovskites would decrease the device performance generally compared to the traditional 3D MAPbI_(3).Incorporation of ultrathin 2D halide perovskite nanosheets(NSs)with 3D MAPbI_(3)could address this issue.Herein,we re port a rationally designed PSCs with dimensional graded 3D/2D MAPbI_(3)/(PEA)_(2)PbI_(4)heterojunction,in which 2D(PEA)_(2)PbI_(4)NSs were synthesized and incorporated between 3D MAPbI_(3)and hole-transporting layer.Besides the significantly improved stability,a notable increasement in power conversion efficiency(PCE)of 20%was obtained for the 3D/2D perovskite solar cells due to the favourable band alignment among(PEA)_(2)PbI_(4)NSs and the other components.The graded structure of MAPbI_(3)/(PEA)_(2)PbI_(4)would upshift the energy level continuously,which enhances the hole extraction efficiency thus reduces the interface charge recombination,leading to the increasements of VOC from1.04 V to 1.07 V,Jsc from 21.81 mA/cm^(2) to 23.15 mA/cm^(2) and the fill factor from 67.89% to 74.78%,and therefore an overall PCE of 18.53%.