Improving the NO<sub>2</sub> Gas Sensing Performances at Room Temperature Based on TiO<sub>2</sub> NTs/rGO Heterojunction Nanocomposites

The development of energy-efficient, sensitive, and reliable gas sensors for monitoring NO<sub>2</sub> concentrations has garnered considerable attention in recent years. In this manuscript, TiO<sub>2</sub> nanotube arrays/reduced graphene oxide nanocomposites with varying rG...

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Main Authors: Yan Ling, Yunjiang Yu, Canxin Tian, Changwei Zou
Format: Article
Language:English
Published: MDPI AG 2024-11-01
Series:Nanomaterials
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Online Access:https://www.mdpi.com/2079-4991/14/22/1844
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author Yan Ling
Yunjiang Yu
Canxin Tian
Changwei Zou
author_facet Yan Ling
Yunjiang Yu
Canxin Tian
Changwei Zou
author_sort Yan Ling
collection DOAJ
description The development of energy-efficient, sensitive, and reliable gas sensors for monitoring NO<sub>2</sub> concentrations has garnered considerable attention in recent years. In this manuscript, TiO<sub>2</sub> nanotube arrays/reduced graphene oxide nanocomposites with varying rGO contents (TiO<sub>2</sub> NTs/rGO) were synthesized via a two-step method for room temperature NO<sub>2</sub> gas detection. From SEM and TEM images, it is evident that the rGO sheets not only partially surround the TiO<sub>2</sub> nanotubes but also establish interconnection bridges between adjacent nanotubes, which is anticipated to enhance electron–hole separation by facilitating electron transfer. The optimized TiO<sub>2</sub> NTs/rGO sensor demonstrated a sensitive response of 19.1 to 1 ppm of NO<sub>2</sub>, a 5.26-fold improvement over the undoped TiO<sub>2</sub> sensor. Additionally, rGO doping significantly enhanced the sensor’s response/recovery times, reducing them from 24 s/42 s to 18 s/33 s with just 1 wt.% rGO. These enhancements are attributed to the increased specific surface area, higher concentration of chemisorbed oxygen species, and the formation of p-n heterojunctions between TiO<sub>2</sub> and rGO within the nanocomposites. This study provides valuable insights for the development of TiO<sub>2</sub>/graphene-based gas sensors for detecting oxidizing gases at room temperature.
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spelling doaj-art-f86c48d1ab1c4149b6b65ce45235faa22024-11-26T18:16:34ZengMDPI AGNanomaterials2079-49912024-11-011422184410.3390/nano14221844Improving the NO<sub>2</sub> Gas Sensing Performances at Room Temperature Based on TiO<sub>2</sub> NTs/rGO Heterojunction NanocompositesYan Ling0Yunjiang Yu1Canxin Tian2Changwei Zou3Key Laboratory of Advanced Coating and Surface Engineering, Lingnan Normal University, Zhanjiang 524048, ChinaKey Laboratory of Advanced Coating and Surface Engineering, Lingnan Normal University, Zhanjiang 524048, ChinaKey Laboratory of Advanced Coating and Surface Engineering, Lingnan Normal University, Zhanjiang 524048, ChinaKey Laboratory of Advanced Coating and Surface Engineering, Lingnan Normal University, Zhanjiang 524048, ChinaThe development of energy-efficient, sensitive, and reliable gas sensors for monitoring NO<sub>2</sub> concentrations has garnered considerable attention in recent years. In this manuscript, TiO<sub>2</sub> nanotube arrays/reduced graphene oxide nanocomposites with varying rGO contents (TiO<sub>2</sub> NTs/rGO) were synthesized via a two-step method for room temperature NO<sub>2</sub> gas detection. From SEM and TEM images, it is evident that the rGO sheets not only partially surround the TiO<sub>2</sub> nanotubes but also establish interconnection bridges between adjacent nanotubes, which is anticipated to enhance electron–hole separation by facilitating electron transfer. The optimized TiO<sub>2</sub> NTs/rGO sensor demonstrated a sensitive response of 19.1 to 1 ppm of NO<sub>2</sub>, a 5.26-fold improvement over the undoped TiO<sub>2</sub> sensor. Additionally, rGO doping significantly enhanced the sensor’s response/recovery times, reducing them from 24 s/42 s to 18 s/33 s with just 1 wt.% rGO. These enhancements are attributed to the increased specific surface area, higher concentration of chemisorbed oxygen species, and the formation of p-n heterojunctions between TiO<sub>2</sub> and rGO within the nanocomposites. This study provides valuable insights for the development of TiO<sub>2</sub>/graphene-based gas sensors for detecting oxidizing gases at room temperature.https://www.mdpi.com/2079-4991/14/22/1844TiO<sub>2</sub> nanotubesreduced graphene oxideNO<sub>2</sub> gas sensingnanocompositesroom temperature sensors
spellingShingle Yan Ling
Yunjiang Yu
Canxin Tian
Changwei Zou
Improving the NO<sub>2</sub> Gas Sensing Performances at Room Temperature Based on TiO<sub>2</sub> NTs/rGO Heterojunction Nanocomposites
Nanomaterials
TiO<sub>2</sub> nanotubes
reduced graphene oxide
NO<sub>2</sub> gas sensing
nanocomposites
room temperature sensors
title Improving the NO<sub>2</sub> Gas Sensing Performances at Room Temperature Based on TiO<sub>2</sub> NTs/rGO Heterojunction Nanocomposites
title_full Improving the NO<sub>2</sub> Gas Sensing Performances at Room Temperature Based on TiO<sub>2</sub> NTs/rGO Heterojunction Nanocomposites
title_fullStr Improving the NO<sub>2</sub> Gas Sensing Performances at Room Temperature Based on TiO<sub>2</sub> NTs/rGO Heterojunction Nanocomposites
title_full_unstemmed Improving the NO<sub>2</sub> Gas Sensing Performances at Room Temperature Based on TiO<sub>2</sub> NTs/rGO Heterojunction Nanocomposites
title_short Improving the NO<sub>2</sub> Gas Sensing Performances at Room Temperature Based on TiO<sub>2</sub> NTs/rGO Heterojunction Nanocomposites
title_sort improving the no sub 2 sub gas sensing performances at room temperature based on tio sub 2 sub nts rgo heterojunction nanocomposites
topic TiO<sub>2</sub> nanotubes
reduced graphene oxide
NO<sub>2</sub> gas sensing
nanocomposites
room temperature sensors
url https://www.mdpi.com/2079-4991/14/22/1844
work_keys_str_mv AT yanling improvingthenosub2subgassensingperformancesatroomtemperaturebasedontiosub2subntsrgoheterojunctionnanocomposites
AT yunjiangyu improvingthenosub2subgassensingperformancesatroomtemperaturebasedontiosub2subntsrgoheterojunctionnanocomposites
AT canxintian improvingthenosub2subgassensingperformancesatroomtemperaturebasedontiosub2subntsrgoheterojunctionnanocomposites
AT changweizou improvingthenosub2subgassensingperformancesatroomtemperaturebasedontiosub2subntsrgoheterojunctionnanocomposites