Risa Suryana, Nida Usholihah, Markus Diantoro,
Volume 21, Issue 2 (June 2024)
Abstract
Modifying photo-anode structures in DSSC devices is still challenging in improving efficiency. This study focused on the ZnO rod growth on several porous silicon substrates using the hydrothermal method and determining which porous silicon is appropriate for DSSC applications. The materials used for the growth solution were Zn(NO3)26H2O 0.05 M and C6H12N4 0.25 M. The hydrothermal process was carried out at 90°C for 6 h and then annealed at 450°C for 30 min. SEM revealed that PSi pore influences the structure, diameter, and density of ZnO rods. ZnO structures formed in ZnO rods with a dominant vertical growth direction, ZnO rods with an intersection direction, and flower-like ZnO rods. The diameter of the PSi pore affected the density of ZnO rods grown on the PSi. The average diameter size and the density of ZnO rods vary from 747.66-1610.68 nm and 0.22-0.90 rod/μm2. XRD confirmed the presence of ZnO hexagonal wurtzite, Si cubic, and SiO2 monoclinic. UV-Vis spectrometry characterization results showed that sample reflectance was influenced by ZnO rod density and PSi pitch. The larger density of ZnO rods and the smaller pitch of the PSi pore will lead to lower reflectance. In addition, band gap values were obtained in the 3.06-3.75 eV range. FTIR identified the existence of a ZnO vibration bond, indicating that ZnO was successfully grown on all PSi substrates. The ZnO rods grown on P15S1180 are expected to have more appropriate properties among all five samples for DSSC photoanode.
Yofentina Iriani, Novia Puspita, Dianisa Sandi, Fahru Nurosyid, Risa Suryana, Didier Fasquelle,
Volume 21, Issue 4 (December 2024)
Abstract
In this research, Lanthanum (La)-doped Strontium Titanate (STO) with the formula of Sr1-xLaxTiO3 (LSTO; x=0, 0.03, 0.05, and 0.07) powders have been successfully fabricated by co-precipitation route. The impacts of La3+ on the structural, microstructure, band-gap, and photocatalytic activity for the degradation of organic pollutants, in this case, methylene blue, under UV exposure, were reported in detail. The formation of undoped and La-doped STO samples with cubic perovskite structures was confirmed by X-ray Diffraction (XRD) results. The presence of La doping affected the microstructure morphology by producing LSTO powders with a larger specific surface area. Besides, the UV absorption of the LSTO powders was enhanced due to the narrowed band gap caused by La3+ dopants. Accordingly, an improvement in photocatalytic activity applied for the photodegradation of methylene blue solution was exhibited by the LSTO samples.
