3D snowflake graphene modified α-MnO2 Catalyst: Enhancing the Low-Temperature catalytic activity for VOCs degradation

•3D snowflake graphene was prepared by “Microwave expansion assisted Hummers method”.•Appropriate graphene doping improves the catalyst morphology and pore structure.•4 %rGO@α-MnO2 has excellent low-temperature catalytic activity and stability.•Graphene doping can build electronic bridges thereby promoting electron transfer.•Graphene can induce the transformation of facet, promoting the formation of Oads.