Microwave-assisted assembly of Ag2O-ZnO composite nanocones for electrochemical detection of 4-Nitrophenol and assessment of their photocatalytic activity towards degradation of 4-Nitrophenol and Methylene blue dye

• Published in: Journal of hazardous materials 2021-08, Vol.416, p.125771, Article 125771
• Main Authors: Chakraborty, Urmila, Bhanjana, Gaurav, Kannu, Kaur, Navneet, Sharma, Ramesh, Kaur, Gurpreet, Kaushik, Ajeet, Chaudhary, Ganga Ram
• Format: Article
• Language: English
• Subjects: Electrochemical sensing; Metal oxide nanocomposite; Photocatalytic degradation; Smart nano-systems
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2021.125771

4-Nitrophenol (4-NP) is an extensively utilized industrial chemical and one of major toxic water pollutant. Therefore, there is an urgent need to monitor the levels of 4-NP from environmental samples as well as its eradication are extremely important. Keeping this as a motivation, this research for the first-time reports microwave-assisted cost-effective synthesis of silver oxide (Ag2O)-zinc oxide (ZnO) composite nanocones (CNCs, 80–100 nm) for simultaneous electrochemical detection and photodegradation of 4-NP from aqueous solutions. The Ag2O-ZnO CNCs modified gold electrode was fabricated for electrochemical detection of 4-NP. Such fabricated sensor exhibited a sensitivity of 1.6 µA µM−1cm−2, wide linear detection range of 0.4–26 µM & 28–326 µM, and a low limit of detection of 23 nM. The sensor also exhibited good selectivity in real water samples. Also, an outstanding photocatalytic performance of Ag2O-ZnO CNCs was evaluated towards UV-assisted degradation of 4-NP and organic water pollutant dye, methylene blue. The Ag2O-ZnO CNCs exhibited excellent electro- and photocatalytic activities due to the formation of p-n nano-heterojunction comprising of p-type Ag2O and n-type ZnO semiconductor nanoparticles within the composite. Therefore, herein reported smart CNCs can be projected as applied nano-system for cost-effective and rapid simultaneous detection and removal of 4-NP from aqueous solutions. Such nano-system can be useful for industrial application where detection and removal of 4-NP is a key issue to resolve. [Display omitted] •Microwave assisted synthesis of Ag2O-ZnO composite nanocones (CNCs) is demonstrated.•Efficient electrochemical detection of 4-NP with Ag2O-ZnO CNCs coated Au electrode.•Sensor exhibits 1.6 µAµM−1cm−2 sensitivity, 0.4–26 µM & 28–326 µM LDR, and LOD of 23 nM.•Complete degradation of MB and 4-NP using CNC under influence of UV light.•CNCs exhibited good sensing as well as photocatalytic activity in real water.