▎ 摘　　要

NOVELTY - A composite gas sensing material comprises 70-99.9 wt.% two-dimensional sheet-like metal oxide and 0.01-30 wt.% graphene quantum dot materials. USE - Composite gas sensing material for detecting formaldehyde gas during preparation of gas sensor (all claimed). ADVANTAGE - The composite gas sensing material has high gas sensitivity to formaldehyde, low working temperature, better interference gas selectivity and high stability. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for the following: (1) a method for preparing a composite gas sensing material (2) a gas sensor (3) a method for preparing a gas sensor.