The chemical experiment is designed for undergraduates majoring in chemistry, energy, and environment. The intended purpose is that the students will comprehend the reaction mechanism of photocatalytic reduction of CO[subscript 2] through hands-on experiments and deepen their understanding of sustainable energy technologies. More importantly, the experiment can make students strengthen the understanding of basic theory of photochemistry and become familiar with the operation process of laboratory instruments, such as a photocatalytic reactor and gas chromatograph. The novel graphene quantum dots/NiAl layered double hydroxide (GQDs/NiAl-LDH) composites are prepared by undergraduates, and the photocatalytic activity is investigated through a series of characterizations and tests. Then the reaction mechanism analysis is carried out in the form of group discussion after the experiment. The student's grade in the laboratory experiment depends on the experimental operation, catalyst synthesis, photocatalytic activity, and mechanism analysis. It is promising that students can organically combine chemistry knowledge with experimental operation through this experiment, so as to encourage them to continue the research related to photocatalytic CO[subscript 2] reduction.