Vapor–Solid Growth of p-Te/n-SnO₂ Hierarchical Heterostructures and Their Enhanced Room-Temperature Gas Sensing Properties

Abstract

We have synthesized brushlike p-Te/n-SnO2 hierarchical heterostructures by a two-step thermal vapor transport process. The morphologies of the branched Te nanostructures can be manipulated by adjusting the source temperature or the argon flow rate. The growth of the branched Te nanotubes on the SnO2 nanowire backbones can be ascribed to the vapor-solid (VS) growth mechanism, in which the inherent anisotropic nature of Te lattice and/or dislocations lying along the Te nanotubes axis should play critical roles. When exposed to CO and NO2 gases at room temperature, Te/SnO2 hierarchical heterostructures changed the resistance in the same trend and exhibited much higher responses and faster response speeds than the Te nanotube counterparts. The enhancement in gas sensing performance can be ascribed to the higher specific surface areas and formations of numerous Te/Te or TeO2/TeO2 bridging point contacts and additional p-Te/n-SnO2 heterojunctions.

Fabrication and characterization of a nanocomposite hydrogel for combined photocatalytic degradation of a mixture of malachite green and fast green dye

“…A constant temperature of 25°C ± 1 was maintained throughout the experiment. 100 mg of the ST/PL(AA-cl-AAm)/Fe/Zn NCHG was added into 2 9 10 -6 M solution of malachite and fast green dye to form slurry [35,36]. The slurry was subjected firstly to adsorption for 1 h kept in dark to attain the adsorption-desorption equilibrium, and after that, it was directly exposed to sunlight for photocatalysis.…”

Quasi-one-dimensional metal-oxide-based heterostructural gas-sensing materials: A review

“…4). The brush-like SnO 2 /Te hierarchical heterostructures have also been synthesized by a two-step thermal vapor transport process [79]. The crystallographic growth directions can be well controlled.…”

“…Te [79]), and other metal nanoparticles can promote the gas response and dynamic characteristics (e.g. reducing response/recovery time) in low concentration.…”

Controlled synthesis of SnO2 hierarchical architectures made of ultrathin nanoflakes for enhanced ethanol gas sensing properties

“…Tian and co-workers [12] prepared 3D hierarchical SnO 2 nanosheets by microwave-assisted synthesis. More morphology includes nanowires [13], nanorods [14], nanobelts [15], flower-like [16], and different hierarchical nanostructures [17][18][19][20][21] were also prepared to improve gas-sensing performance of SnO 2 . Of all the morphologies, three-dimensional (3D) nanostructures exhibit better gas-sensing performance.…”