Sacrificial Reducing Agent Free Photo-Generation of Platinum Nano Particle over Carbon/TiO2 for Highly Efficient Oxygen Reduction Reaction

Abstract

Electrocatalytic materials for oxygen reduction reaction, currently dominated by platinum/carbon catalyst is marred by drawbacks such as use of copious amount of Pt and use of “non-green” sacrificial reducing agent (SRA) during its synthesis. A single stroke remedy for these two problems has been achieved through an in-situ aqueous photoreduction void of even trace amounts of SRA with an enhanced activity. Reduction of PtCl62− salt to Pt nano particles on carbon substrate was achieved solely using solar spectrum as the source of energy and TiO2 as photocatalyst. Here, we demonstrate that this new procedure of photoreduction, decorates Pt over different types of conducting allotropes with the distribution and the particle size primarily depending on the conductivity of the allotrope. The Pt/C/TiO2 composite unveiled an ORR activity on par to the most efficient Pt based electrocatalyst prepared through the conventional sacrificial reducing agent aided preparation methods.

Overestimation of Photoelectrochemical Hydrogen Evolution Reactivity Induced by Noble Metal Impurities Dissolved from Counter/Reference Electrodes

“…The peaks were deconvoluted with Pt 0 (71.2 eV), Pt 2+ (72.4 eV), and Pt 4+ (73.7 eV) species, showing a predominant presence of metallic Pt 0 . 39 Hence, redeposition of Pt on the aged p-Si surface was identified. Interestingly, clear peaks (more intense than those of XPS-Pt 4f ) were observed at 368.4 and 374.4 eV in the XPS spectrum (Figure 2d), which were assigned to 3d 5/2 and 3d 3/2 of metallic Ag 0 , respectively.…”

“…The XPS-Pt 4f spectrum of pristine p-Si showed no discernable peaks from the Pt species (Figure S3), although they were present for the aged sample (Figure c). The peaks were deconvoluted with Pt 0 (71.2 eV), Pt 2+ (72.4 eV), and Pt 4+ (73.7 eV) species, showing a predominant presence of metallic Pt 0 . Hence, redeposition of Pt on the aged p-Si surface was identified.…”

Oxygen Reduction Reaction Performance Tuning on Pt Nanoparticle/MWCNT Catalysts by Gd Species

“…Numerous strategies involving platinum (Pt) nanoparticle catalysts on carbon supports (Pt/C) have been explored to improve the cathode catalytic performance (oxygen reduction reaction (ORR)) of Pt nanoparticles for polymer electrode fuel cells. − For instance, various methods for the size regulation of Pt nanoparticles/nanoclusters, , structural or morphological control of Pt nanoparticles, − ,− alloying of other metal species to Pt nanoparticles, − ,,,− and surface modification with organic molecules/polymers − or metal oxides/oxinitrides/nitrides/chalcogenides, − ,− as well as combinations of these methods, have been reported to increase the ORR activity of Pt nanoparticle catalysts.…”

“…The modification of Pt/C-based catalysts with transition/main-group metal oxides (e.g., TiO x , − FeO x , TaO x , − and SnO x − ) has been explored as a facile and efficient method for promoting ORR performance with respect to both activity and durability. For example, the strong metal–support interaction between Pt nanoparticles and TaO x was proposed to be a key factor underlying the enhanced ORR activity because of the improved adsorption of O 2 on the Pt surface due to facilitated cleavage of O–O bonds. ,, A Pt 3 Co/C catalyst functionalized with SnO 2 nanoislands also exhibited significant improvements in the ORR activity and durability compared with a nonfunctionalized commercial Pt 3 Co/C catalyst, and the interface between the SnO 2 nanoislands and Pt 3 Co nanoparticles was suggested to provide superior active sites .…”

Synthesis of Ultrafine Platinum Nanocatalysts by Ice‐photochemical Method and Their Application in Catalytic Degradation of 4‐nitrophenol

“…Figure 1a shows the complete XPS spectra of the three samples. The binding energy peaks at 284.8, 531.2 and 71.2 eV were attributed to the chemical binding energy of C1s, O1s and Pt4 f , respectively, [25] which confirmed the existence of C, O and Pt.…”