Effective reduced graphene oxide sheets/hierarchical flower-like NiO composites for methanol sensing under high humidity

Author(s)

Zito, Cecilia A. ^[1] ; Perfecto, Tarcisio M. ^[1] ; Fonseca, Cristiane S. ^[1] ; Volanti, Diogo P. ^[1]

Affiliation

^[1] Sao Paulo State Univ Unesp, Lab Mat Sustainabil LabMatSus, R Cristovao Colombo 2265, BR-15054000 Sao Jose Do Rio Preto, SP - Brazil

• Document type: Journal article
• Source: NEW JOURNAL OF CHEMISTRY; v. 42, n. 11, p. 8638-8645, JUN 7 2018.
• Web of Science Citations: 7

Abstract

Recent advances in NiO-based gas sensors have been reported, but high working temperatures and dry conditions are usually required. Herein, we report the volatile organic compound (VOC) sensing performance of flower-like (FL) NiO hierarchical structures modified with reduced graphene oxide (RGO) sheets under high humidity. RGO/FL-NiO composites were synthesized by a simple and template-free microwave-assisted hydrothermal method and subsequent calcination at 250 degrees C. The VOC-sensing properties were investigated for several VOCs, such as acetone, ethanol, methanol, m-xylene, and toluene, at 90% relative humidity. The RGO/FL-NiO composites exhibited a decrease in the optimal operating temperature and enhanced methanol responses compared to pure FL-NiO. In addition, the 5% RGO/FL-NiO composite exhibited the highest response of 61.51% to 100 ppm of methanol at 180 degrees C, which was 1.4-9.9 times superior to responses to other VOCs, indicating the sensor's great selectivity. The improved methanol sensing properties could be attributed to the NiO/RGO heterointerface. (AU)

• FAPESP's process: 16/04371-1 - Sensors based on reduced graphene oxide-WO3 and Ag-WO3 obtained by microwave-assisted ultrasonic spray and deposited on paper for detection of volatile organic compounds
• Grantee: Tarcísio Micheli Perfecto
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 17/01267-1 - Graphene acid-hollow metal oxides composites for gas sensor
• Grantee: Diogo Paschoalini Volanti
• Support Opportunities: Regular Research Grants
• FAPESP's process: 13/23886-4 - Study on selectivity of hydrogenolysis / reductive hydrogenation processes of sugarcane bagasse under supercritical state catalyzed by structured metal oxides
• Grantee: Mauricio Boscolo
• Support Opportunities: Program for Research on Bioenergy (BIOEN) - Regular Program Grants
• FAPESP's process: 16/25267-8 - Graphene acid composites with hollow CeO2 and Pd-CeO2 yolk-shell structures applied as volatile organic compounds sensors
• Grantee: Cecilia de Almeida Zito
• Support Opportunities: Scholarships in Brazil - Doctorate