TY - JOUR

T1 - S, N Co-Doped Carbon Dot-Functionalized WO3Nanostructures for NO2and H2S Detection

AU - Patel, Chandrabhan

AU - Mandal, Biswajit

AU - Jadhav, Rohit G.

AU - Ghosh, Tapas

AU - Dubey, Mayank

AU - Das, Apurba K.

AU - Htay, Myo Than

AU - Atuchin, Victor V.

AU - Mukherjee, Shaibal

N1 - Funding Information: Authors are thankful to the Sophisticated Instrumentation Centre (SIC) of IIT Indore for providing the characterization facility (SEM, XRD, and Raman) and also CEERI Pilani, India for the lithography facility. They are also grateful to Mr. Tomohiko Yamakami of the Technical Division, Faculty of Engineering, Shinshu University for HR-TEM imaging. This work is also partially funded by MHRD STARS (Project No. STARS/APR2019/NS/116/FS dated February 5, 2020). This work was partly supported by the Ministry of Science and Higher Education of Russia (project 075-15-2020-797 (13.1902.21.0024)). Authors would like to thank TIH-IOT CHANAKYA Group (PhD, PG, and UG) Fellowship Programme 2021-2022 (Doc No. TIH-IOT/12/2022/CHANAKYA/Group/Sanction Letter/004) for providing the fellowship. Publisher Copyright: © 2022 American Chemical Society. All rights reserved.

PY - 2022/2/25

Y1 - 2022/2/25

N2 - This paper reports the synthesis of a S, N co-doped carbon dot (C-dot)-functionalized WO3 (C(S, N)-WO3) nanostructure via a hydrothermal method, which exhibits ultrasensitivity for NO2 at the ppb level and H2S at the ppm level along with remarkable selectivity. The WO3 morphology is optimized by varying the pH (1.5-3.5) of the solution. Characterization results reveal that the surface morphology at pH 3 is superior for producing uniform nanoneedle nanostructures with high sensitivity toward NO2 and H2S. To further enhance the sensitivity and selectivity of WO3 nanoneedles, the effect of mixing of C-dots into WO3 is investigated systematically. The optimized weight of C-dots in the C(S, N)-WO3 composite is 10 mg, which exhibits sensitivity values of 2.2 to 250 ppb for NO2 and 29.5 to 100 ppm for H2S. The C(S, N)-WO3 composite material shows the highest sensitivity at an optimum substrate temperature of 150 °C, without an obvious influence of humidity up to 50% relative humidity. The limit of detection of the composite sensor is 250 ppb NO2 along with excellent repeatability and good long-term stability.

AB - This paper reports the synthesis of a S, N co-doped carbon dot (C-dot)-functionalized WO3 (C(S, N)-WO3) nanostructure via a hydrothermal method, which exhibits ultrasensitivity for NO2 at the ppb level and H2S at the ppm level along with remarkable selectivity. The WO3 morphology is optimized by varying the pH (1.5-3.5) of the solution. Characterization results reveal that the surface morphology at pH 3 is superior for producing uniform nanoneedle nanostructures with high sensitivity toward NO2 and H2S. To further enhance the sensitivity and selectivity of WO3 nanoneedles, the effect of mixing of C-dots into WO3 is investigated systematically. The optimized weight of C-dots in the C(S, N)-WO3 composite is 10 mg, which exhibits sensitivity values of 2.2 to 250 ppb for NO2 and 29.5 to 100 ppm for H2S. The C(S, N)-WO3 composite material shows the highest sensitivity at an optimum substrate temperature of 150 °C, without an obvious influence of humidity up to 50% relative humidity. The limit of detection of the composite sensor is 250 ppb NO2 along with excellent repeatability and good long-term stability.

KW - doped carbon dot

KW - functionalized WO

KW - gas sensor

KW - pH variation

KW - ultrasensitivity

UR - http://www.scopus.com/inward/record.url?scp=85124137850&partnerID=8YFLogxK

U2 - 10.1021/acsanm.1c04174

DO - 10.1021/acsanm.1c04174

M3 - Article

AN - SCOPUS:85124137850

VL - 5

SP - 2492

EP - 2500

JO - ACS Applied Nano Materials

JF - ACS Applied Nano Materials

SN - 2574-0970

IS - 2

ER -