G.N. Chaudhari

Bio: G.N. Chaudhari is an academic researcher from Sant Gadge Baba Amravati University. The author has contributed to research in topics: Nanocrystalline material & Thin film. The author has an hindex of 18, co-authored 42 publications receiving 934 citations.

Structural and gas sensing properties of nanocrystalline TiO2:WO3-based hydrogen sensors

Abstract: Nanocrystalline TiO2:WO3-based hydrogen sensors have been developed by using a sol-precipitation method. Structural and gas-sensing characteristics were performed by using XRD and resistivity measurements. XRD of TiO2 calcined at 600 °C for 6 h showed good crystalline quality having a 54 nm grain size. Although these elements were rather slow in response rate, this could be improved significantly by loading the elements further with a noble metal. The operating temperature of the sensors was optimized under different operating conditions. A TiO2:15 wt.% WO3 sensor doped with 0.5 wt.% Pt showed the maximum response to H2 with a good selectivity at an operating temperature of 200 °C. The response time of the TiO2:15 wt.%WO3 sensor decreased from about 20 min to 1 min with the Pt-loading. The effect of platinum was seen not only in decreasing the response rate but also in increasing considerably the response to H2. The electronic interaction between the additive and the oxide semiconductor is proposed to account for the sensitization effects.

Recent advancements in the cobalt oxides, manganese oxides and their composite as an electrode material for supercapacitor: a review

Abstract: In this smart edge, there is an intense demand of portable electronic devices such as mobile phones, laptops, smart watches etc. That demands the use of such components which has light weight, flexible, cheap and environmental friendly. So that needs an evolution in technology. Supercapacitors are energy storage devices emerging as one of the promising energy storage devices in the future energy technology. Electrode material is the important part of supercapacitor. There is much new advancement in types of electrode materials as for supercapacitor. In this review, we focused on the recent advancements in the cobalt oxides, manganese oxides and their composites as an electrodes material for supercapacitor.

Ferromagnetic materials

Abstract: In this chapter, we will restrict our attention to the ferrites and a few other closely related materials. The great interest in ferrites stems from their unique combination of a spontaneous magnetization and a high electrical resistivity. The observed magnetization results from the difference in the magnetizations of two non-equivalent sub-lattices of the magnetic ions in the crystal structure. Materials of this type should strictly be designated as “ferrimagnetic” and in some respects are more closely related to anti-ferromagnetic substances than they are to ferromagnetics in which the magnetization results from the parallel alignment of all the magnetic moments present. We shall not adhere to this special nomenclature except to emphasize effects, which are due to the existence of the sub-lattices.

Ultracapacitors: Why, How, and Where is the Technology

Abstract: The science and technology of ultracapacitors are reviewed for a number of electrode materials, including carbon, mixed metal oxides, and conducting polymers. More work has been done using microporous carbons than with the other materials and most of the commercially available devices use carbon electrodes and an organic electrolytes. The energy density of these devices is 3¯5 Wh/kg with a power density of 300¯500 W/kg for high efficiency (90¯95%) charge/discharges. Projections of future developments using carbon indicate that energy densities of 10 Wh/kg or higher are likely with power densities of 1¯2 kW/kg. A key problem in the fabrication of these advanced devices is the bonding of the thin electrodes to a current collector such the contact resistance is less than 0.1 cm2. Special attention is given in the paper to comparing the power density characteristics of ultracapacitors and batteries. The comparisons should be made at the same charge/discharge efficiency.

Semiconducting metal oxides as sensors for environmentally hazardous gases

Abstract: This article extensively reviews the recent development of semiconductor metal oxide gas sensors for environmentally hazardous gases including NO2, NO, N2O, H2S, CO, NH3, CH4, SO2 and CO2. The gas sensing properties of differently-prepared metal oxides and loaded metal oxides towards nine environmentally hazardous gases have been individually compared and digested. Promising materials for sensitive and selective detection of each hazardous gas have been identified. For instance, unloaded WO3 nanostructures are the most promising candidates for NO2 sensing while metal catalyst loaded WO3 and gold-loaded SnO2 sensors are among the most effective for NO and N2O sensing, respectively. Moreover, related gas-sensing mechanisms are comprehensively discussed.

Ultrawide-Bandgap Semiconductors: Research Opportunities and Challenges

Abstract: J. Y. Tsao,* S. Chowdhury, M. A. Hollis,* D. Jena, N. M. Johnson, K. A. Jones, R. J. Kaplar,* S. Rajan, C. G. Van de Walle, E. Bellotti, C. L. Chua, R. Collazo, M. E. Coltrin, J. A. Cooper, K. R. Evans, S. Graham, T. A. Grotjohn, E. R. Heller, M. Higashiwaki, M. S. Islam, P. W. Juodawlkis, M. A. Khan, A. D. Koehler, J. H. Leach, U. K. Mishra, R. J. Nemanich, R. C. N. Pilawa-Podgurski, J. B. Shealy, Z. Sitar, M. J. Tadjer, A. F. Witulski, M. Wraback, and J. A. Simmons