Electrochemical and optical band gaps of bimetallic silver-platinum varying metal ratios nanoparticles

Abstract

Simultaneous citrate reduction of various ratios of silver and platinum ions leads to the formation of core-shell nanostructured bimetallics (BM). Transmission electron microscopy (TEM) and X-ray diffraction XRD data of the BMs depicted crystalline core -shell nanoparticles consisting of Ag core and Pt shell with an average size of 22.2 nm in contrast to the Pt NPs and Ag NPs monometallics average sizes of 2.5 and 60.0 nm respectively. Tauc's calculated optical band gaps ranged from 3.55 to 4.02 eV while the electrochemical based on Breda's equation had a range of 1.45 to 1.80 eV. These band gaps range variation maybe due to inter atomic interaction, morphology and quantum confinement. Generally, bimetallics had higher band gaps relative to monometallics. The Ag: Pt ratio of 3:1 had the highest optical band gap and the smallest particle size. While the ratio of 1:3 had the highest electrochemical band gap as well as the largest particle size among the BMs. Suggesting band gap dependence on amount of Ag and Pt for optical and electrochemical respectively.

Optimization Method Based on Simplex for Surface Area Improved Photocatalytic Performance of g-C3N4

“…As can be observed from the results listed in Table , the values of E g el and E g opt are different. The reason for the larger E g opt in comparison to the E g el is probably the effect of (i) morphology and quantum confinement and (ii) the effect of the solvent, temperature, and electrolyte. , In particular, the morphology and quantum confinement effect explain the increased (∼0.32 eV) E g opt in all Simplex-optimized photocatalysts in comparison to the E g opt of the MRref sample. In the case of electrochemical determination, these two effects do not play a crucial role, and the E g el values are more in the expected (moderate) range.…”

Improvement of light-harvesting efficiency of amorphous silicon solar cell coated with silver nanoparticles anchored via (3-mercaptopropyl) trimethoxysilane

“…Besides absorbance, Table 3 also shows that with increasing R value, the wavelength of the absorption peak shifted from 451.80 nm to 438.30 nm, while the calculated E pa increases from 2.75 eV to 2.83 eV. According to Fredrick and Mangaka (2016), the plasmon absorption energy of the metallic nanoparticles is dependent on their particle size. The increase in the plasmon absorption energy (E pa ) indicates that smaller nanoparticles have been synthesized when a higher concentration of NaBH 4 was used.…”

“…311) have been reported byFredrick and Mangaka (2016). All the diffraction peaks shown in the XRD pattern correspond to the face-centered cubic (FCC) structure of Ag NPs and indicate the crystalline nature of Ag NPs(Erjaee et al 2017).…”