https://scholar.dgist.ac.kr/handle/20.500.11750/1194 2026-11-15T15:28:25Z https://scholar.dgist.ac.kr/handle/20.500.11750/61170 Title: Designing high performance MXene supercapacitors through functionalization and defect engineering: A theoretical study Author(s): Khan, Ziaul Raza; Ahmad, Sarfraz; Ahmad, Pervaiz; Imran, Muhammad; Hussain, Fayyaz; Bouzidi, M.; Mohamed, Mansour; Khalil, R.m.a.; Irfan, Muhammad; Arooj, Aqsa Abstract: Supercapacitors (SCs) have attracted significant attention as energy storage devices due to their large power efficiency, excellent stability, prolonged cycle life and short recharge time. Ti-based MXenes have attracted considerable attention as promising candidates for SC electrodes due to their extraordinary physicochemical properties, such as high charge storage capacity, excellent electrical conductivity, unique layered structure, and the presence of multiple surface functional groups. In this study, Ti2CX2 (X = Cl, F, Br, O, P, S, Se, Si and Te) MXene, both with and without carbon vacancies, were investigated as SC electrode materials using DFT. The structural stability, dynamic stability, density of states, quantum capacitance, average quantum capacitance, surface charge density, work function, integrated charge density, isosurface charge density difference, and bader charge analysis of all MXenes are studied. Results revealed that CQ and Q significantly changed due to varying the functional group, and introduction of carbon vacancy significantly enhanced the CQ and Q. For the aqueous system, all MXene exhibited asymmetrical behavior except Ti2CF2 + VC and Ti2CP2 + VCMXenes. The calculated results illustrate that Ti2CTe2 + VC (478 & micro;C & sdot;cm-2) and Ti2CSi2 + VC (-750.7 & micro;C & sdot;cm-2) MXenes are the best anode and cathode respectively. In the case of an ionic/organic system, all MXenes exhibited asymmetrical behavior. The calculated findings show that Ti2CTe2 (1136.9 & micro;C & sdot;cm-2) and Ti2CSi2 + VC (-930.7 & micro;C & sdot;cm-2) MXenes are the best anode and cathode respectively. The work function of Ti2CTe2, Ti2CTe2 + VC and Ti2CSi2 + VCMXenes is lower than that of the other investigated MXenes, indicating that power efficiency of these MXenes based SCs is high. The findings reveal that Ti2CTe2, Ti2CTe2 + VC and Ti2CSi2 + VCMXenes give better results as compared to previously reported Ti-based MXenes, positioning them as strong candidates for next-generation SC electrodes. 2026-05-31T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/61154 Title: Poling-tunable self-powered ultraviolet-C photodetection in mechanochemically derived HfO2–Ga2O3–ZnO/polyethyleneimine composite films Author(s): Huy, Vo Pham Hoang; Vo, Thi Muoi; Park, Jae Ho; Bark, Chung Wung Abstract: Distinct from previously reported HfO2/Ga2O3 layered heterostructures, in which HfO2 1–2 nm insulating interlayer was used and the device operated mainly under external bias, our work presents a mechanochemically derived HfO2–Ga2O3–ZnO multicomponent composite, a PEI-modified interface, a self-powered response at 0 V, and negative pre-poling used to tune the zero-bias response/noise balance. Polyethyleneimine (PEI) was used as a surface and interfacial modifier to form HGZO@PEI films with improved optoelectronic characteristics. Space-charge-limited current (SCLC) analysis yielded an effective electron mobility of 2.01 × 10−2 cm2 V−1 s−1 for HGZO@PEI, higher than the values obtained for the HfO2–ZnO (HZO), Ga2O3–ZnO (GZO), HfO2–Ga2O3 (HGO), and HGZO counterparts under the reported analysis conditions. Under 254 nm ultraviolet-C (UVC) illumination, the device exhibited repeatable zero-bias photoresponse and retained 94.6% of its initial photocurrent after seven days and 85.44% after 50 cycles. Importantly, the HGZO@PEI device operates in a self-powered mode without requiring electrical pre-poling, while negative pre-poling provides an additional means to tune the interfacial electronic environment and balance photoresponse against noise characteristics. This material–interface–field engineering strategy offers a distinct route toward low-power, tunable solar-blind UVC photodetection. 2027-01-31T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/61153 Title: Valorization of Agave amica leaf waste into high-performance natural fibers for polymer composites Author(s): Shibly, Mohammad Abul Hasan; Sabit, Marat; Sen, Prosenjit; Al Nahid, Abdullah; Shoshi, Khadiza Siddika; Das, Niloy krishna; Hasan, Muhammad Kamrul; Sabur, Md. Abdus; Rahman, Mohammad Mahbubur Abstract: This study reports the extraction and characterization of Agave amica leaf fibers (AALFs), an underutilized agricultural by-product, as a sustainable reinforcement for polymer composites. Fibers were extracted via eco-friendly hot-water retting and sun-drying, exhibiting a fineness of 12.65 ± 3.25 tex, density of 1.08 ± 0.055g cm⁻³, and moderate cellulose content (53.45 wt%). Structural analyses (XRD, FTIR, SEM–EDS) confirmed a crystalline, fibrillated morphology compatible with polymer matrices. Mechanical testing showed tensile strengths of 52–57MPa and Young’s modulus of 1.68–1.84 GPa, while thermal stability up to ~ 245°C enables processing under common composite manufacturing conditions. These results demonstrate the potential of AALFs as lightweight, sustainable reinforcement for polymer composites in automotive, packaging, and textile applications, supporting circular economy and waste valorization strategies. 2026-11-30T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/61149 Title: Triboelectric interface using waste-derived jamun seed powder and EVA composites for self-powered handwriting recognition Author(s): Mohanty, Raj; Bhosale, Premkumar; Hajra, Sugato; Behera, Swayam Aryam; Panigrahi, Basanta Kumar; Vivekananthan, Venkateswaran; Kim, Hoe Joon; Vittayakorn, Naratip; Achary, P.Ganga Raju Abstract: The use of waste-based biomaterials for energy harvesting is a new frontier in triboelectric nanogenerator (TENG) research and self-powered sensing systems. In this study, we demonstrate a triboelectric interface based on jamun seed powder embedded in an ethylene-vinyl acetate (EVA) polymer matrix for handwriting recognition. Jamun seed waste contains cellulose, lignin, polyphenols, and oxygenated functional groups, which contribute to the accumulation of surface charge during contact electrification. The optimal peak-to-peak output voltage and current of the EVA-JB composite at 15 wt% filler (EVA-JB15 abbreviated) loading was 260 V and 1500 nA, respectively. XRD- and FTIR-based structural evaluation showed that the filler was successfully incorporated into the EVA matrix without disturbing the basic semicrystalline polymer structure. The composite has an increased dielectric constant (∼4.55 at 10 kHz), suggesting higher charge storage capacity and interfacial polarisation than the pure EVA. The produced TENG exhibited a maximum power of 78.125 μW at the 200 MΩ external load resistance. A convolutional neural network (CNN) model was trained using TENG-derived handwriting signals from five individuals and obtained an overall classification accuracy of 99.18%. This study opens a possible path towards triboelectric interfaces for advanced self-powered sensing. 2026-12-31T15:00:00Z