摘要
Photodeposition has been used extensively for nanomaterial growth on a substrate, but direct photodeposition of 2D transition metal dichalcogenides (TMDs) remains challenging. An alternative approach is to deposit 2D TMDs on a suitable nanomaterial template. In this work, large-scale MoS 2 /Cu 2 O/ZnO heterostructure arrays are formed by low-temperature in situ photodeposition and the nanocomposites are used for chemiresistive gas sensing at room temperature. Using 254 nm UV irradiation, Cu 2 O nanoclusters are photodeposited in solution on hydrothermally grown ZnO nanorod arrays and Cu 2 O/ZnO heterostructure arrays are first formed. MoS 2 nanoparticles are subsequently photodeposited on Cu 2 O and MoS 2 /Cu 2 O/ZnO heterostructure arrays with good uniformity on a sub-millimeter scale are consequently produced. The ternary nanocomposite with a 45 min MoS 2 photodeposition time shows the highest response of 890% toward 500 ppb NO 2 under UV-activated sensing. An excellent linear sensitivity of 18.7 ppm –1 has been achieved and the estimated lowest detection limit is 1.3 ppb, exhibiting good potential for monitoring of environmental NO 2 content. The outstanding performance is attributed to the combined chemical and electronic sensitization effects of the abundant heterojunctions in the nanocomposite. The present work reveals that facile in situ photodeposition is suitable for synthesis of large-scale MoS 2 /Cu 2 O/ZnO heterostructure arrays with remarkable gas sensing performance.