Pisith Singjai

Accumulation of soil and surface reflection significantly compromise the energy yield of photovoltaic (PV) modules. This study presents a scalable, solvent-free approach to fabricating multifunctional coatings via magnetic-field-assisted spark ablation. Comparative analysis confirms that replacing conventional Ti with Sn accelerates the deposition rate by threefold while maintaining photocatalytic efficiency comparable to benchmark TiO₂. Furthermore, we demonstrate that applying an in-situ external magnetic field acts as a critical phase modulator, stabilizing a unique biphasic SnO₂–SnO heterojunction and promoting dense nanoparticle aggregation. Importantly, the combined effect of material substitution (Sn instead of Ti) and magnetic-field-optimized scanning results in an overall increase in deposition speed by 5.25-fold, establishing this method as an exceptionally rapid and industrially viable solution. The optimized coating enhanced the solar panel’s power conversion efficiency (PCE) by 4.02% under clean conditions. Significantly, under simulated muddy-water exposure, the coated modules exhibited superior anti-soiling capabilities, achieving a net PCE gain of 6.00% relative to uncoated panels. The coating also demonstrated exceptional mechanical robustness, retaining structural integrity after 10,000 water-impact cycles. These findings establish the process as a rapid, industrially viable technique for producing durable, high-efficiency surfaces.

The superhydrophobic, self-cleaning and anti-corrosion surface was successfully coated on mortar using an effective one-step spray coating technique. A coating solution was prepared by mixing methyltrichlorosilane-modified SiO2/TiO2 nanoparticles at different ratios to enhance the superhydrophobicity and reduce water absorption of the mortar. The sample prepared using a SiO2/TiO2 with the ratio of 75/25 was found to be optimal, exhibiting a high water contact angle and low sliding angle, which resulted in a reduction of water absorption by more than 97.5 % and chloride ion penetration depth. Furthermore, the robustness of the superhydrophobic coating was analyzed against various tests including water drop impact, sand abrasion impact, tape peeling and sandpaper abrasion tests, each test was conducted with over 10000 drops, 300 g, 60 cycles and 5 cycles, respectively. Notably, the coating showed excellent water absorption reduction of 82.6 % after sandpaper abrasion for a length of 200 cm (20 cycles), even though the water contact angle was reduced to 118?. Thus, the fabrication of superhydrophobic mortar surface offers a novel, alternative approach that is simple, efficient, cost-effective and provides multifunction protection surface to increase the service life of on-site building construction with enhanced mechanical durability and anti-corrosion properties.

Developing long-lasting humidity sensors is essential for sustainable advancements in nanotechnology. Prolonged exposure to high humidity can cause sensors to drift from their calibration points, leading to long-term accuracy issues. Our research aims to develop a fabrication method that produces stable sensors capable of withstanding the environmental challenges faced by humidity sensors. Traditional iron-based nanoparticles often require complex treatments, such as chemical modification or thermal annealing, to maintain their properties. This study introduces a novel, one-step synthesis method for iron-based thin films with exceptional stability. The synthesized films were thoroughly characterized using X-ray photoelectron spectroscopy (XPS) to evaluate their phase stability and nitride formation. The method proposed in this study employs an electrical sparking discharge process within a pure nitrogen atmosphere under a 0.2 T magnetic field, producing thin films composed of nanoparticles approximately 20 nm in size. The resulting films demonstrate superior performance in humidity sensing applications compared to conventional methods. This straightforward and efficient approach offers a promising path toward robust and sustainable humidity sensors.

The sparking discharge process utilises high voltage to melt and evaporate tips of electrodes to create particles that can be deposited on substrate. In our research, we examine the influence of a magnetic field and nitrogen flow on gold thin-film formation onto quartz substrate. A positive effect of nitrogen flow and a 0.3 T external magnetic field was observed, in enhancement of surface plasmon band in UV visible and dispersal of nanoparticles without agglomeration. We also detected and described nitrification occurrences of gold measured by XPS at 407 eV and nitridification of quartz substrate on which gold particles are collected. These nitrogen-based chemical reactions occurred during sparking of gold wire inside of ambient air and in the magnetic field, as well during pure nitrogen flow. We measured the valence band electronic structure of gold nanoparticles deposited onto quartz substrate and found that gold thin film prepared in the magnetic field under nitrogen flow has the lowest value of 1.5 eV. Preparation of gold thin films in the magnetic field under nitrogen flow offers a highly dispersed and convenient method for productions of thin films.