Scalable production of intrinsic WX₂(X = S, Se, Te) quantum sheets for efficient hydrogen evolution electrocatalysis

Mass production of transition-metal dichalcogenides has attracted much attention to replace platinum-based catalysts for the hydrogen evolution reaction (HER). Herein, we demonstrate a general strategy for the scalable production of the intrinsic tungsten dichalcogenide (WX₂(X = S, Se, Te)) quantum sheets (QSs) by an all-physical top-down method. The method combines silica-assisted ball-milling and sonication-assisted solvent exfoliation and thus enables production of WS₂QSs, WSe₂QSs, and WTe₂QSs in exceedingly high yields of 28.2, 21.3, 19.9 wt%, respectively. The WX₂QSs are confirmed as intrinsic and defect-free, which could be determinative to their improved HER performance. The overpotentials of 285, 331, 435 mV at the current density of 10 mA cm^-2and Tafel slopes of 116, 78, 162 mV dec^-1in acidic media, as well as charge transfer resistance values of 171, 242, 1973 Ω, are derived for WS₂QSs, WSe₂QSs, and WTe₂QSs, respectively, which are much better than those of bulk materials. The WX₂QSs exhibit high stability during the electrocatalysis as well. This work offers a powerful approach for fabrication of intrinsic QSs as efficient and robust electrocatalysts.