https://scholar.dgist.ac.kr/handle/20.500.11750/1921 2026-10-06T22:13:28Z https://scholar.dgist.ac.kr/handle/20.500.11750/60906 Title: Stable UiO-66/BaTiO3 Heterostructure for Efficient Solar-Light Ciprofloxacin Degradation and Energy Harvesting Applications Author(s): Dhal, Bikash Chandra; Bhosale, Premkumar Sharad; Hajra, Sugato; Panda, Swasti Padma; Das, Abhijeet; Dutta, Basudeb; Kim, Hoe Joon; Sahu, Rojalin Abstract: The fabrication of robust metal-organic frameworks (MOFs) continues to be difficult in materials science studies. In order to overcome such an obstacle, the design of hybrid framework materials could be an effective solution. Herein, we successfully synthesized UiO-66/BaTiO3 hybrids with different percentages of BaTiO3 mass (10%-50%), which are intended to improve the photocatalytic activity. Considering the widespread pollution of water resources with ciprofloxacin (CIP), leading to the emergence of antibiotic resistance, urgent treatment measures are needed. The optimized U/BTO-25 hybrid showed remarkable photocatalytic activity, with CIP removal reaching 98.37% in 30 min. Such excellent catalytic behavior is due to the complementary nature of both components, where the large specific surface area of UiO-66 helps with the adsorption of CIP, while ferroelectric polarization of BaTiO3 leads to charge separation. In particular, the radical trapping experiments center dot O2 - and h+ to be the dominant radicals. The hybrid showed excellent stability in four successive cycles with a slight decline in efficiency. In addition, the hybrid has significant prospects for use in triboelectric nanogenerators. The output of the nanogenerator was 73 V and 180 nA, respectively, and the output can be harvested in a capacitor to power off-the-shelf electronic devices, demonstrating the potential of MOF-ferroelectric hybrid materials. 2026-05-31T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/60892 Title: Revealing the flexoelectricity and flexocatalysis of BiOI nanoplates: new insight into the powerful catalytic material Author(s): Das, Tushar Kanti; Jesionek, Marcin; Mistewicz, Krystian; Toron, Bartlomiej; Godzierz, Marcin; Kepinska, Miroslawa; Starczewska, Anna; Zubko, Maciej; Hajra, Sugato; Jana, Runia; Bhosale, Premkumar; Kim, Hoe Joon Abstract: Flower-like BiOI nanoplates were successfully synthesized via a simple and eco-friendly chemical precipitation route and evaluated as flexocatalysts for the ultrasonic degradation of organic pollutants. The synthesized BiOI exhibited a well-defined layered structure with abundant crystal defects, including a high dislocation density and bismuth vacancies, together with a narrow band gap of 1.935(2) eV, which are favourable for catalytic activity. The material demonstrated an intrinsic flexoelectric coefficient of 12.00(8) pC/N, enabling efficient conversion of mechanical energy into electrical polarization under ultrasonic excitation. Consequently, the BiOI nanoplates exhibited outstanding flexocatalytic performance toward sonodegradation of Congo Red, achieving a degradation rate constant of 1.45 & times; 10-3 s-1. The enhanced catalytic activity is attributed to strain-gradient-induced flexoelectric polarization, which facilitates efficient charge separation and promotes the generation of reactive oxygen species. Comparative analysis further revealed that the catalytic performance of BiOI is comparable to or exceeds that of many reported metal oxide and metal oxide-based nanocatalysts. These findings establish flower-like BiOI nanoplates as an efficient and sustainable flexocatalyst and demonstrate the potential of exploiting flexoelectricity to develop mechanically driven catalytic systems for wastewater treatment and environmental remediation. 2026-08-31T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/60871 Title: Exploring the potential of multifunctional MWCNT/PDMS nanocomposites in thermal and mechanical energy harvesting Author(s): Talaniuk, Viktoriia; Mistewicz, Krystian; Gawron, Anna; Marcinkowski, Andrzej; Szeluga, Urszula; Myalska-Głowacka, Hanna; Kaja, Kushal Ruthvik; Hajra, Sugato; Kim, Hoe Joon; Godzierz, Marcin Abstract: In this work, it was shown that a nanocomposite of multi-walled carbon nanotubes (MWCNTs) and polydimethylsiloxane (PDMS) is a versatile material that can convert both thermal and mechanical energy into electrical energy. The MWCNT/PDMS nanocomposite with a MWCNT concertation of 2 mass% was chemically etched to expose the carbon nanotubes on the surface of the nanocomposite. This resulted in a significant reduction in contact resistance, an increase in electrical conductivity, and consequently, an improvement in thermoelectric properties. For the first time, the MWCNT/PDMS nanocomposite was thoroughly analyzed to characterize its thermoelectric and triboelectric properties. Electrical conductivity, specific heat, thermal diffusivity, and thermal conductivity were investigated as a function of temperature in a wide range from 298 to 373 K. The optimized characteristics of the MWCNT/PDMS nanocomposite were achieved due to its relatively high electrical conductivity (22 S cm(-1)) and low thermal conductivity (0.22 W m(-1) K-1). The Seebeck coefficient and thermoelectric efficiency factor were found to increase with temperature, reaching the maximum values of 4.6 mu V K-1 and 7.4 & centerdot;10(-5), respectively. The MWCNT/PDMS nanocomposite was used as a negative friction layer in a triboelectric nanogenerator (TENG). This device operated in contact-disconection mode, generating an output voltage of 7 V and a current of 113 nA. During long-term testing, the TENG demonstrated exceptional stability and repeatability of its voltage response. It was shown that the MWCNT/PDMS-based TENG is suitable for harvesting mechanical energy from human body movements, such as finger tapping, foot tapping, and hammering. The developed MWCNT/PDMS nanocomposite shows great potential for use in flexible wearable sensors for self-powered temperature monitoring and motion detection. 2026-04-30T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/60870 Title: Self-poled and poling-free efficient piezoelectric nanogenerators for power generation and self-powered applications Author(s): Kumar, Naveen; Kaja, Kushal Ruthvik; Panda Swati; Hajra Sugato; Belal, Mohamed Ahmed; Bhosale, Premkumar Sharad; Khanapuram, Uday Kumar; Rajaboina, Rakesh Kumar; Keum, Hohyun; Lee, Kyoungtae; Kim, Hoe Joon Abstract: Piezoelectric nanogenerators (PENGs) have emerged as promising energy harvesters capable of converting waste mechanical energy into usable electrical power for self-powered electronic applications. Traditionally, PENGs require an external poling process to align ferroelectric dipoles and achieve efficient operation. However, reliance on high-voltage poling, time-consuming processing, and potential material degradation limits the scalability and practicality of conventional PENGs. Recent research has therefore focused on developing self-poled, polingfree PENGs that offer intrinsic polarization, enhanced stability, and simplified fabrication without external treatments. This review summarizes the fundamental working principles of PENGs and the effect of polarization on their performance. Then, an in-depth discussion of the concept and comparison between the self-poling and poling-free mechanisms is provided. Recent advances in self-poled or poling-free PENGs, material innovations, including polymers, ceramics, and composites, as well as device engineering strategies that enable efficient energy conversion without external poling, are also demonstrated. The review concludes with significant challenges, including material durability, large-scale fabrication, and integration into complex systems, as well as future research prospects for developing next-generation self-powered technology. By integrating current advances and highlighting key obstacles, the review attempts to offer valuable insights into the future development of efficient, scalable, and environmentally sustainable poling-free PENGs. To the best of our knowledge, this is the first comprehensive review of self-poled and poling-free PENGs, focusing on underlying mechanisms, material fabrication methods, and emerging applications. 2026-05-31T15:00:00Z