SiNW/C@Pt Arrays for High-Efficiency Counter Electrodes in Dye-Sensitized Solar Cells

Abstract

Modern energy needs and the pressing issue of environmental sustainability have driven many research groups to focus on energy-generation devices made from novel nanomaterials. We have prepared platinum nanoparticle-decorated silicon nanowire/carbon core–shell nanomaterials (SiNW/C@Pt). The processing steps are relatively simple, including wet chemical etching to form the silicon nanowires (SiNWs), chemical vapor deposition to form the carbon shell, and drop-casting and thermal treatment to embed platinum nanoparticles (Pt NPs). This nanomaterial was then tested as the counter electrode (CE) in dye-sensitized solar cells (DSSCs). SiNW/C@Pt shows potential as a good electrocatalyst based on material characterization data from Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). Raman spectroscopy shows that the surface reactivity of the SiNW/C is increased by the decoration of Pt NPs. These data also show that the carbon shell included both graphitic (sp 2 hybridization) and defective (sp 3 hybridization) phases of carbon. We achieved the minimum charge-transfer resistance of 0.025 Ω · cm 2 and the maximum efficiency of 9.46% with a symmetric dummy cell and DSSC device fabricated from the SiNW/C@Pt CEs, respectively.

Facile Green Approach for Developing Electrochemically Reduced Graphene Oxide-Embedded Platinum Nanoparticles for Ultrasensitive Detection of Nitric Oxide

“…All the respective spectral analogues of C 1s, O 1s, and Pt 4f were deconvoluted and fitted by using the Gaussian function. As shown in Figure b, the C 1s spectra were deconvoluted into three different peaks at 284.6, 286.71, and 288.96 eV corresponding to the C–C, C–O, and CO bonds of rGO present in SQ-I and SQ-II, respectively. , Furthermore, the O 1s spectrum (Figure c) was deconvoluted with several peaks at 531.48, 532.39, and 533.15 eV corresponding to Pt–O, CO, and C–O for both SQ-I and SQ-II. , Additionally, the SQ-II peak at 535.58 eV was noted and assigned to chemisorbed water molecules, which limit the NO detection efficiency for SQ-II compared to SQ-I. More importantly, the Pt 4f high-resolution spectra (Figure d) were deconvoluted into three different chemical states of Pt.…”

“…Also, peaks at binding energy (BE) values of 70.1 and 73.6 eV are ascribed to the spin orbit coupling pair of Pt 4f 7/2 and Pt 4f 5/2 of the Pt +2 state present in SQ-I, respectively. Additionally, the peaks at 70.7 and 74.6 eV are attributed to the pair of Pt 4f 7/2 and Pt 4f 5/2 confirming the presence of the Pt +4 oxidation state in SQ-I as demonstrated in Figure d. , Similarly, in the case of SQ-II, a positive shift was observed in the BE value because of the reduction in electron density of metallic Pt.…”

“…22 To explore the chemical constitution and valence state of the surface elements present in SQ-I and SQ-II, the X-ray photoelectron spectroscopic (XPS) analysis was employed and the results obtained are shown in Figure 4a 4d. 70,71 Similarly, in the case of SQ-II, a positive shift was observed in the BE value because of the reduction in electron density of metallic Pt. 2.2.…”

Effect of Molybdenum Disulfide on the Performance of Polyaniline Based Counter Electrode for Dye-Sensitized Solar Cell Applications

“…The counter electrode acts as a cathode, which is responsible for accepting electrons from the outer circuit and regenerating electrolytes. The limited availability and expensive nature of Pt limits the use of DSSC technology and is probably one of the main hurdles in the commercialization of this technology [6,7]. Various materials and their combinations have been tried to replace Pt with promising results.…”