Efficient deconstruction of Chinese silvergrass by FeCl3-catalyzed γ-valerolactone/water system under mild reaction condition

•FeCl3-catalyzed GVL pretreatment facilitated efficient deconstruction of CS.•The pretreated CS had poor lignin but rich cellulose on surface.•Tween 80 was more effective than XYL in enhancing enzymatic hydrolysis of the CS.•The highest glucose yield obtained from CS by enzymatic hydrolysis was 99.7 %.