▎ 摘　　要

The surface functionalization of graphene nanoplatelets catalysts (GNPs) with -OH, -COOH, and -SO3H groups for cellulose hydrolysis was investigated via gas-liquid interfacial plasma (GLIP) sulfonation system under 1 M H2SO4. The sulfonation chemistry of the GLIP process was examined under different gas ratios of N-2/Ar (100%N-2, 70%N-2-30%Ar, 30%N-2-70%Ar). The balance between plasma-induced physical activation and chemical reaction plays an essential part in the sulfonation performance. Experiments on acidic group determination and catalysis ability test demonstrated that the addition of 30% Ar to N-2 exerts a positive effect on enhancing the sulfonation activity and catalytic stability of GNPs. The 70%N-2-30%Ar-GNPs shown higher total acid and sulfonic acid density of 5.56 and 0.45 mmol g(-1), respectively. The optimized catalyst achieved a conversion rate of 41.5% with high glucose selectivity of 84.3%. Sulfonation of GNPs over traditional hydrothermal method under 18 M H2SO4 at 200 degrees C for 24 h further reflected the "less hazardous" and "high efficiency" properties of GLIP sulfonation in 1 M H2SO4 for 1 h. Significantly, the GLIP-GNPs also exhibited superior recyclability of 95.9% in 3 times cycle tests for cellulose hydrolysis, which is much higher than that of H-GNPs (49.5%).