MoS₂ Nanoribbons With A Prolonged Photoresponse Lifetime For Enhanced Visible Light Photoelectrocatalytic Hydrogen Evolution

The increasingly serious global energy crisis and accompanying environmental problems have prompted scientists to constantly look for environmentally friendly and sustainable new energy sources to replace traditional fossil fuels.The development of clean,cheap and sustainable fuel production and application technologies is a major challenge for the former world.In many energy systems,hydrogen has a higher specific energy than most hydrocarbons,and only releases water when burned.It is a clean,sustainable,and ideal new energy source for replacing fossil fuels.Hydrogen evolution from water electrolysis is considered to be the best technology to adjust the balance between renewable energy power generation and end-use energy demand in the future hydrogen energy cycle.It provides an effective way to solve the increasingly serious energy shortage problem.Devices that promote water electrolysis,including electrochemical and photoelectrochemical cells（PEC）,these emerging technologies have the potential to regenerately produce clean hydrogen fuel from water without the need for fossil fuels or harmful by-products.The high recombination rate of photo-induced electron-hole pairs limits the hydrogen production efficiency of MoS₂catalyst in photoelectrochemical（PEC）water splitting.Strategy of prolonging the lifetime of photo-induced carriers is of great significance to the promotion of photoelectrocatalytic hydrogen production.An ideal approach is to utilize edge defects,which can capture photo-induced electrons and thus slow down the recombination rate.However,for 2D MoS₂,most of surface areas are inert basal plane.Here,a simple method for preparing 1D MoS₂nanoribbons with abundant inherent edges is proposed.The MoS₂nanoribbon-based device has a good spectral response in the range of 400-500 nm and has longer lifetime of photo-induced carriers than other MoS₂nanostructures-based photodetectors.An improved PEC catalytic performance of this MoS₂nanoribbons is also experimentally verified under the illumination of 405 nm by using electrochemical microcell technique.The work provides a new strategy to prolong the lifetime of photo-induced carriers for further improvement of PEC activity,and the evaluation of photoelectric performance provides a feasible way for transition metal dichalcogenides to be widely used in energy field.