Willy Satrio Nugroho

Dye-sensitized solar cells (DSSCs) continue to face performance limits driven by electron recombination and insufficient light harvesting. This study examines the influence of a SiO2 interlayer on the structural, optical, and photovoltaic properties of TiO2 photoelectrodes employed in DSSCs with a resin-based electrolyte. TiO2-SiO2 composites were synthesized and systematically characterized to evaluate morphology, surface behavior, and device performance. SEM and spectroscopic analyses show that SiO2 incorporation modifies surface topology and enhances light scattering, contributing to more efficient charge transport. UV-Vis measurements reveal a broadened absorption profile in TiO2-SiO2 photoelectrodes, indicating improved photon utilization. Current-voltage (I-V) testing further demonstrates that DSSCs incorporating TiO2-SiO2 achieve higher power conversion efficiency than those using pristine TiO2, attributable to enhanced electron mobility and reduced recombination. These results highlight the effectiveness of SiO2 modification in optimizing TiO2-based DSSCs and provide a promising pathway for advancing next-generation solar cell technologies.

Enhancing the kinetics of the hydrogen evolution reaction (HER) in alkaline water electrolysis is crucial for producing hydrogen effectively and affordably. The use of sodium lauryl sulfate (SLS) as a surfactant additive in chloride-free NaOH electrolytes on SS316L electrodes is examined in this work. MixedNaOH-SLS electrolytes dramatically lower apparent onset potentials, decrease Tafel slopes, and enhance interfacial charge storage and long-term stability, according to electrochemical tests such as linear sweep voltammetry, Tafel plots, cyclic voltammetry, and chronoamperometry. The optimalNaOH-SLS ratio (7:1:2) outperforms both pure NaOH and SLS-rich electrolytes by achieving the lowest apparent onset potential and the highest sustained current density. Surfactant-induced micelle formation and Na⁺-OH⁻ clusters increase ion mobility and modify the electrical double layer, allowing charge transfer without changing the electrode surface, according to FTIR analysis. These findings demonstrate a non-catalytic, interface-driven strategy to improve alkaline HER, providing a workable way to produce hydrogen steadily and effectively using commercially viable stainless-steel electrodes.

Hydrogen production using photocatalysis with activated carbon (AC) combined with curcumin and CTP has been investigated. Curcumin contains two aromatic rings and two ”“OH groups, while CTP contains two aromatic rings, one pyran heterocyclic ring, and six ”“OH groups at specific positions. However, the combined performance of these materials with AC has not been fully optimized, highlighting the need for further research to understand their chemical interactions in photocatalytic processes and their potential for renewable energy applications. This study aimed to determine the role of pyran heterocyclic rings and ”“OH groups in hydrogen production. The results showed that hydrogen production using pure AC was 115.75 μmol/g, while AC + curcumin and AC + CTP produced 1297.8 μmol/g and 1462.6 μmol/g, respectively. The higher hydrogen production in AC + CTP compared to AC + curcumin is attributed to the presence of pyran heterocyclic rings, which enhance photocatalyst stability and efficiency by reducing electron”“hole recombination and expanding the light absorption spectrum, thereby increasing hydrogen evolution. Although the stacking interactions and active sites in the form of ”“OH, C”“H, and C”“O groups in AC + CTP are fewer than in AC + curcumin, the presence of oxygen atoms in the pyran heterocyclic ring contributes to greater hydrogen production. This study contributes to the selection of effective photocatalyst materials based on compound composition to support clean and sustainable hydrogen energy as an alternative to fossil fuels.

The object of this study is the carbon-based organic capacitors, derived from bagasse leaves from the Kebon Agung sugar factory, Malang, Jawa Timur, serving as a sustainable precursor material. The challenge of optimizing the performance of bagasse leaf-based organic capacitors has been a significant barrier in advancing sustainable electronic components. This study aims to develop a quality framework for synthesizing these capacitors by systematically optimizing the parameters using the Taguchi method. Traditional methods often lead to inconsistent performance and high variability, making it difficult to achieve reliable results. By applying the Taguchi orthogonal array, this study identified key factors and optimal levels, effectively reducing experimental efforts while ensuring robust performance. The carbonization of bagasse leaves was conducted using direct combustion with thinner and 70% methanol as liquid burners. Capacitance tests revealed stable values ranging from 0.8897 nF to 0.9281 nF across trials, demonstrating consistent and reproducible behavior. Thermal noise evaluation showed slight temperature variations (69.01°C to 72.01°C), indicating the influence of temperature on electron mobility within the dielectric materials. The systematic approach of the Taguchi method minimized variability and enhanced the capacitors' reliability under varying thermal conditions. The method's focus on robustness and quality control ensured consistent capacitance values and improved overall capacitor performance. Compared to traditional methods, the Taguchi method facilitated a thorough exploration of the design space with fewer experiments. This study underscores the importance of systematic optimization in capacitor design, offering a reliable pathway to integrate sustainable materials into advanced electronic components. The results provide valuable insights into the effects of different parameters on performance metrics, enhancing the development of high-quality organic capacitors

Sumber Rejeki Welding Workshop is one of the small and medium enterprises engaged in manufacturing and welding services in Malang City. In its production process, the workshop still relies on conventional welding methods that are less efficient and produce suboptimal weld quality. Therefore, this community service program aims to enhance production efficiency and quality by implementing Gas Tungsten Arc Welding technology and assisting in applying occupational health and safety standards. The implementation method of this program includes several stages: the preparation stage, which involves identifying partner needs and machine installation; the training stage, consisting of theoretical and practical sessions for operators; the production assistance stage; and the evaluation stage, using the Non-Destructive Testing method with penetrant testing techniques to assess weld quality. The results of this program implementation indicate a 30% improvement in production efficiency, with reduced processing time and fewer welding defects. Significant economic impacts are also evident through increased production capacity and the workshop's competitiveness in the local market. Furthermore, the provided training has enhanced the operators' skills in machine operation and raised their awareness of the importance of occupational safety standards. This program demonstrates that adopting modern welding technology can significantly improve productivity and product quality, making it a potential model for application in other small and medium enterprises to boost competitiveness in the manufacturing sector.

This study investigates the synthesis, characterization, and photovoltaic performance of a rice husk-based TiO2-SiO2 hybrid organic thin film, which serves as the photoactive layer in an organic photovoltaic (OPV) cell. The object of the study is the TiO2-SiO2 hybrid thin film derived from rice husk, developed to enhance solar energy conversion in OPV applications. Conventional TiO2 thin films typically exhibit low efficiency due to limited electron mobility, small surface area, and weak photon absorption. To overcome these limitations, silicon dioxide (SiO2) was sustainably extracted from rice husk and integrated with TiO2 to form a hybrid material with improved structural and electronic properties. Structural analysis confirmed the formation of a porous composite that enhances charge separation and facilitates more efficient electron transport. Optical studies revealed increased photon absorption across the UV-visible spectrum due to synergistic interactions between TiO2 and SiO2. XRD analysis indicated that the hybrid structure improves crystallinity and potentially enhances carrier mobility. Furthermore, the surface passivation effect of SiO2 helps reduce charge recombination by mitigating defect states in the TiO2 matrix. The fabricated OPV device achieved an open-circuit voltage of 0.72 V, a short-circuit current density of 4.6 mA/cm², and a power conversion efficiency of 2.8 %, exceeding the performance of conventional TiO2-based cells. This enhancement is attributed to optimized charge transport and improved interfacial interaction. The approach demonstrates a sustainable and cost-effective route for high-performance thin-film solar cells using agricultural waste, particularly beneficial for regions with abundant solar energy and limited technological infrastructure