Ultrahigh Selective Room-Temperature Ammonia Gas Sensor Based on Tin–Titanium Dioxide/reduced Graphene/Carbon Nanotube Nanocomposites by the Solvothermal Method

Abstract

Resistive-based gas sensors have been considered as the most favorable gas sensors for detection of toxic gases and volatile organic compounds (VOCs) because of their simple structure, low cost, high sensitivity, ease of use, and high stability. Unfortunately, wide application of resistive-based gas sensors is limited by their low selectivity. In this article, we present the fabrication of ultrahigh selective NH3 gas sensor based on tin–titanium dioxide/reduced graphene/carbon nanotube (Sn–TiO2@rGO/CNT) nanocomposites. The Sn–TiO2@rGO/CNT nanocomposites with different molar ratios of Sn/Ti (1:10, 3:10, and 5:10) were synthesized via the solvothermal method. Characterizations by scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy confirmed the decoration of Sn–TiO2 nanoparticles on rGO/CNT nanocomposite surfaces. The Sn–TiO2@rGO/CNT nanocomposite gas sensor exhibited high response and ultrahigh selectivity to NH3 against toluene, dimethylformamide, acetone, ethanol, methanol, isopropanol, formaldehyde, hydrogen, carbon dioxide, acetylene, and VOCs in paint thinners at room temperature. The Sn–TiO2@rGO/CNT nanocomposite gas sensor with molar ratio of Sn/Ti = 1:10 showed the highest response to NH3 over other molar ratios of Sn/Ti as well as pure rGO/CNT and Sn–TiO2 gas sensors. The ammonia-sensing mechanisms of the Sn–TiO2@rGO/CNT gas sensor were proposed based on the formation of p–n heterojunctions of p-type rGO/CNT and n-type Sn–TiO2 nanoparticles via a low-temperature oxidizing reaction process.

On‐Site Detection for Hazardous Materials in Chemical Accidents

“…(c) Ultrahigh selective NH 3 gas sensor based on nanocomposites 61 . Reproduced with permission 49,61,65 …”

“…(b) A fiber‐optic probe for HF acid detection by reflection‐based localized surface plasmon resonance 49 . (c) Ultrahigh selective NH 3 gas sensor based on nanocomposites 61 . Reproduced with permission 49,61,65 …”

“…49 (c) Ultrahigh selective NH 3 gas sensor based on nanocomposites. 61 Reproduced with permission. 49,61,65 from the perspective of industry properties, ensuring safety for humans, and the environment (Scheme 1).…”

A Highly Sensitive Room Temperature CO2 Gas Sensor Based on SnO2-rGO Hybrid Composite

“…Synergistic hybridization of rGO with metal oxide particles has been an effective way to greatly improve gas detection because it combines both materials’ traits and enhances gas sensing capabilities toward various gases. Many composite modifications have been made, such as the formation of SnO 2 /rGO [ 22 , 23 , 24 , 25 , 26 , 27 ], zinc oxide/reduced graphene oxide (ZnO/rGO) [ 28 ], cobalt oxide/reduced graphene oxide (Co 3 O 4 /rGO) [ 29 ] and tin-titanium dioxide/reduced graphene oxide/carbon nanotube (Sn–TiO 2 /rGO/CNT) [ 30 ]. These composites exhibit good gas detection, including enhanced sensitivity at room temperature.…”

Fabrication of a Greener TiO2@Gum Arabic-Carbon Paste Electrode for the Electrochemical Detection of Pb2+ Ions in Plastic Toys

“… 5 − 9 TiO 2 nanoparticles (TiO 2 NPs) are widely used in the fabrication of gas sensors, which can detect various different gases including oxidative gases (O 2 , NO 2 ) and reductive gases (H 2 , CO, NH 3 , H 2 S, VOCs), organophosphorus, toxic organic solvents, and amperometric biosensors. 10 − 14 Heavy metal pollution is one of the most serious problems in the world and poses major threats to the health and well-being of millions of people and global ecosystems because of their dramatic increase from both anthropogenic and natural sources. Heavy metals such as lead (Pb) are hazardous pollutants because they affect human health even at very low concentrations and induce high toxicity and considerable carcinogenicity.…”