In this paper,the collective effects of combining heterogeneous Ag/TiO_2 nanocomposite catalyst with the byproducts(primarily the irradiation and the O_3 species) of an atmospheric pressure plasma jet(APPJ) system on the degradation of methyl orange(MO) were explored.The heterostructured Ag/TiO_2 nanocomposite was achieved via decorating the Ag quantum dots(QDs) on the commercially available TiO_2catalyst(P25) through a hydrothermal method.The x-ray diffraction analysis of the nanocomposite catalyst showed the diffraction peaks at 44.3°,64.4°,and 77.5°,corresponding to the Ag planes of(200),(220) and(311),respectively.The high resolution transmission electron microscope characterization of the nanocomposite catalyst indicated that the Ag QDs with an average diameter of 5 nm were homogeneously distributed on the P25 surface.The experimental results on the MO photodegradation showed that the APPJ irradiation had a marginal effect on the cleavage of the MO molecules.When the Ag/TiO_2 nanocomposite catalyst was used,the photodegradation rate of MO increased about 5 times.When both the APPJ byproducts and the Ag/TiO_2 nanocomposite catalyst were used,however,over 90% of the MO in the tested solution was cleaved within 15 min,and the energy efficiency was about 0.6 g/k W h.Moreover,an optimal Ag dosage value was determined(6 wt%).The catalytic results indicated that combining the DBD plasma byproducts with heterogeneous nanocomposite catalysts may be an effect protocol for decreasing the application cost of the DBD system and mitigating the environment pollution by organic dyes in the textile industry. In this paper, the collective effects of combining heterogeneous Ag / TiO_2 nanocomposite catalyst with the byproducts (to the irradiation and the O_3 species) of an atmospheric pressure plasma jet (APPJ) system on the degradation of methyl orange (MO) were explored.The heterostructured Ag / TiO 2 nanocomposite was achieved via decorating the Ag quantum dots (QDs) on the commercially available TiO 2 catalyst (P25) through a hydrothermal method. The x-ray diffraction analysis of the nanocomposite catalyst showed the diffraction peaks at 44.3 °, 64.4 °, respectively. The high resolution transmission electron microscope characterization of the nanocomposite catalyst indicated that the Ag QDs with an average diameter of 5 nm were homogeneously distributed on the P25 surface. The experimental results on the MO photodegradation showed that the APPJ irradiation had a marginal effect on the cleavage of the MO molecules. When the Ag / TiO 2 n anocomposite catalyst was used, the photodegradation rate of MO increased about 5 times. Both of the APPJ byproducts and the Ag / TiO 2 nanocomposite catalyst were used, however, over 90% of the MO in the tested solution was cleaved within 15 min, and the The catalytic results indicated that combining the DBD plasma byproducts with heterogeneous nanocomposite catalysts may be an effect protocol for decreasing the application cost of the DBD system and mitigating the environment pollution by organic dyes in the textile industry.