| With the rapid development of global industrialization and world economy,both energy crisis and environmental pollution become more and more conspicuous problems.Importantly,these problems will directly or indirectly endanger the healthy growth and development of humans,animals and plants,and ultimately lead to ecological destruction.Therefore,it is urgent to seek renewable,clean energy and develop efficient organic pollutant treatment and pathogenic microorganism inactivation technologies.In recent years,electrocatalytic water splitting technology and semiconductor photocatalytic technology have gradually come into people’s field of vision due to the advantages of green pollution-free and energy saving.The development of high-efficiency and low-cost catalytic materials is a key issue facing the further development of electro/photocatalytic technology.Transition metal-based compounds have become the focus of research in the field of electrocatalysis and photocatalysis due to their abundant reserves and unique d-orbital electronic structure.However,the catalytic performance of single component electrocatalytic materials is often restricted by conductivity,active sites and other factors;single semiconductor photocatalytic materials usually have some serious problems such as low solar energy utilization,easy recombination of photo-generated carriers.This paper uses experimental/computational simulation methods to construct several transition metal-based heterostructures,and focuses on their electro/photocatalytic properties and their performance enhancement mechanisms that can be applied to life sciences and other fields.The heterogeneous NiFe based oxide/phosphide(NiFe2O4/NiFeP)nanoplates are synthesized on Ni foam using selective phosphorization process with double crucibles in muffle furnace.The constructed NiFe2O4/NiFeP heterostructure shows superior catalytic performance for oxygen evolution reaction(OER).Impressively,the optimal NiFe2O4/NiFeP heterostructure demonstrates a low overpotential of 191 mV to afford an anodic current density of 10 mA cm-2 in 1M KOH,which is better than most of reported OER electrocatalysts.The superior OER activity can be ascribed to the well-configured 3D network structure composed of vertically interlaced nanoplates to provide more active sites exposed and the optimal electronic structure arisen from the synergistic effect between NiFe2O4 and NiFeP to facilitate charge separation and reduce the energy barrier.This selective phosphorization strategy enables rational construction of oxides/phosphides heterostructures with superior OER performance.In addition,this work provides a feasible way for the efficient development of hydrogen energy and even the improvement of the ecological environment.A 2D MoS2/SnS heterostructure is constructed,and its structural characteristics and electronic properties are comprehensively investigated using first-principles calculations.It is found that the MoS2/SnS heterostructure is a stable interface and forms a type-II heterostructure,which defnitely facilitates the spatial separation and migration of photoexcited electron-hole pairs under light irradiation.More importantly,a relatively small band gap(roughly 0.29 eV)enables its light absorption spectrum to cover the entire visible light region.Interestingly,the Mo atoms in the MoS2/SnS heterostructure would turn into catalytic active sites.As a result,constructing heterostructure of MoS2 with SnS improves light absorption,accelerates the separation of electronhole pairs,and activates the Mo atom at the basal plane,all of which could be benefcial to the photocatalytic activity.This work provides monolayer MoS2-based heterostructure photocatalysts and insightful understanding of their physical mechanism,and lays a certain theoretical foundation for the practical application of MOS2/SnS heterostructure material to solve the problems in the field of life science such as the inactivation of harmful microorganisms and the degradation of cell dyeing dyes. |
PDF Full Text Request