Ultrasonically synthesized MgZnO nanoparticles for enhanced piezo-photocatalysis and MgZnO/p-Si heterojunction diode characteristics

ABSTRACT

Limitations in practical implementations of ZnO nanomaterials could be solved by tuning the properties of ZnO via doping process. We have doped the Mg²⁺ ions in the ZnO nanostructures (MgZnO) via the ultrasonic synthesis procedure. The structural study revealed the shrinkage of the crystallite size of the wurtzite system for Mg²⁺ doping concentration. The TEM images revealed the morphological changes for Mg²⁺ doping from particulate (50 nm) to nanoflower structures (200 nm) in ZnO. Optical studies revealed the enhanced UV photons absorption and emission intensities for Mg doped ZnO compared to pristine ZnO. The calculated bandgap values from the absorption spectroscopy of the ZnO, MgZnO-1, MgZnO-3, and MgZnO-5 are 3.34 eV, 3.40 eV, 3.51 eV, and 3.57 eV. The prepared MgZnO/p-Si heterojunction diodes showed excellent rectification behavior and enhanced electrical properties for Mg²⁺ doping. The diode obtained with 5% of Mg²⁺ had exhibited the ideality factor value of 3.1. Pristine ZnO had exhibited only 66% of photocatalytic methylene blue (MB) degradation efficiency. One hundred percent degradation of MB had been achieved via piezo-photocatalytic effect with 5% Mg²⁺ doped ZnO, whereas piezocatalysis and photocatalysis had shown 82% and 98% respectively.

KEYWORDS:

• Mg doped ZnO
• Optical properties
• P-si
• heterojunction
• piezo-photocatalysis

Highlights

• Ultrasonically synthesized MgZnO nanoparticles exhibited 100% of methylene blue degradation under sunlight-assisted piezo-photocatalytic conditions.

• We have successfully developed the Mg²⁺ doped ZnO nanoparticles using the ultrasonication-assisted co-precipitation strategy.

• The Mg²⁺ ions doping had modified the nanoparticulate morphology to the nanoflower-like morphology.

• The band gap value of the ZnO had blue shifted for the Mg²⁺ ions doping.

• n-MgZnO/p-Si heterojunction diodes fabricated with the ultrasonically synthesized MgZnO nanoparticles had shown the better rectification ratio.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Notes on contributors

Saravanan Pandiyaraj

Saravanan Pandiyaraj has completed his Under-Graduate in Electronics and Communication Engineering from St. Joseph’s College of Engineering and Technology and completed his Post-Graduation M.Tech., in Nanoscience & Technology from Anna University, Trichy. Currently pursuing Ph.D. in the area of Nanotechnology based Opto-electronics from K.Ramakrishnan College of Engineering affiliated to the Anna University, Chennai. His area of interests is Optoelectronics, Solar Cells and Photocatalysts.

Maheswari Murali

Maheswari Murali has completed her UG in Electronics and Communication Engineering from Bharathiyar University, Coimbatore, Post-graduation M.Tech., from National Institute of Technology, Trichy and PhD from Anna University, Chennai. She has 25 years of teaching experience. Her areas of interests are VLSI signal Processing, Reliability of on chip interconnects and Transceiver design for 5G communication. She has published more than 25 papers in reputed International journals which includes Springer, Elsevier and indexed in SCI, Scopus and WoS. She has presented more than 25 papers in reputed International Conferences. She is currently working as Professor and Head, Department of Electronics and Communication Engineering, K. Ramakrishnan College of Engineering, Tiruchirappalli, Tamilnadu, India. She has received Fund of Rs. 17.5 Lakhs from Various funding agencies like AICTE, EDII, TNSCST for MODROB, FDP etc. She has also published 6 Indian patents and 1 Australian patent. Presently 9 research scholars are doing research under her guidance.

Suresh Muthusamy

Suresh Muthusamy received the bachelor’s degree in Electrical and Electronics Engineering and the master’s degree in Power Electronics and Drives during the year 2009 and 2011 from Anna University, Chennai and Anna University, Coimbatore, respectively. Currently, he is working towards the Ph.D. degree in Electrical Engineering at Anna University, Chennai in the area of Hybrid Renewable Energy Systems and waiting for the viva-voce examination. He worked as Assistant Professor in the Department of Electrical and Electronics Engineering at Kongu Engineering College (Autonomous), Perundurai, Erode, during the period June 2011 to January 2020. From January 2020 onwards, he has been working as Assistant Professor Senior Grade in the Department of Electronics and Communication Engineering at Kongu Engineering College (Autonomous), Perundurai, Erode. He published more than 100 research articles in well reputed and refereed international journals from Elsevier, Springer, Taylor & Francis, SAGE, ASME, ASTM International, MDPI, CRC Press, etc. and indexed in SCI, SCIE, ESCI, Scopus and Web of Science with good impact factors. He also presented several research articles in national and international conferences and also serving as the reviewer, editor for about 60 international journals including IET Renewable Power Generation, IET Journal of Engineering, etc. To his credit, he has filed and published 28 Indian patents in IPR website, governed by Ministry of Commerce and Industry, Government of India. His areas of interests include hybrid renewable energy systems, power electronic converters, hybrid electric vehicles, and battery management systems.

Hitesh Panchal

Hitesh Panchal received the bachelor’s degree in Mechanical Engineering from Government Engineering College, Modasa, Gujarat during the year 2004 and the master’s degree in Internal Combustion Engines and Automobile from L.D. College of Engineering, Ahmedabad, Gujarat during the year 2006. He then received the Ph.D degree in Mechanical Engineering in the area of Solar Thermal Engineering from K.S.V. University, Gandhinagar, Gujarat in 2015. Dr. Panchal has published more than 150 research articles in reputed National and International Journal publications like Taylor and Francis, Springer, Elsevier, ASME, SAGE, etc. and also received 6986+ Google Scholar citations with h-index of 51 and i-10 index of 154. Dr.Panchal received many prestigious awards like Best Ph.D Thesis Award, Bharat Excellence Award, Young Scientist Award, Bright Researchers Award and many more from various organizations. Dr.Panchal has completed 2 Research projects from GUJCOST, DST of 15 lakhs and currently working on one Research project from DTE. Dr.Panchal has filed 24 full patents & 10 Industrial designs and among them 2 patents & 7 industrial designs has been granted. Dr.Panchal has been selected in “Top 2% Indian Scientist under the energy category” published by Stanford University for the year 2020 and 2021.