Fabrication of High-Activity Hybrid Pt@ZnO Catalyst on Carbon Cloth by Atomic Layer Deposition for Photoassisted Electro-Oxidation of Methanol

Abstract

ZnO nanorods with a diameter of 25 nm have been synthesized on carbon cloth (CC) by combining atomic layer deposition (ALD) and hydrothermal methods. Platinum nanoparticles were then deposited on photoinduced hydrophilic surface of ZnO nanorods by ALD. Electrochemical performance of the nanocomposite catalyst (Pt@ZnO@CC) for methanol oxidation with or without UV irradiation was evaluated. According to the X-ray photoelectron spectroscopic (XPS) analysis, the surface of ZnO nanorods rich in hydroxide species was more favorable for removal of CO via the so-called bifunctional mechanism. Additionally, the XPS study indicates that the charge transfer occurs between the ZnO nanorods and the Pt nanoparticles. UV light irradiation on the catalyst surface increases the chronoamperometric response by 62%, which is attributed to a synergistic effect of large surface area and strong light absorption in the UV region by the presence of ZnO nanorod arrays.

The Applications of Morphology Controlled ZnO in Catalysis

“…One-dimensional ZnO nanostructures have been intensively investigated in photoelectrochemical (PEC) cells to split water and large enhancements have been achieved [74,77,79,[82][83][84]. Furthermore, ZnO nanorods have been reported in the applications of photoelectron-oxidation of ethanol and methanol [83,84]; ZnO has also been applied as an important photoelectrocatalyst component in the methanol production from CO 2 by photoelectrocatalytic reduction. Therefore, applications of morphology controlled ZnO in the photoelectron oxidation of organic substances to generate hydrogen or electricity and photoelectron reduction of CO 2 to produce fuels should be further investigated.…”

“…Since oxide semiconductors were discovered employed as photoanodes in photoelectrochemical (PEC) cells to split water, it has become an exciting subject of research, as mentioned in the Introduction section [82][83][84]263]. However, in fact, photoelectron-oxidation of organic substances to produce hydrogen is much more efficient than PEC cells to split water [82].…”

“…Besides, photoelectron-oxidation of organic substances is also possible to produce electricity, called Photo Fuel Cell (PFC) [82]. The incorporation of large band-gap semiconductor photocatalysts is reported to efficiently minimize CO positioning in photoelectron oxidation of organic substances [83,84].…”

“…Similarly, Su et al explored the electro-chemical performance of methanol oxidation over Pt@ZnO nano-rods @CC (CC: carbon cloth) electrode with or without UV irradiation [84]. With irradiation, Pt@ZnO@CC electrode demonstrated 90% higher methanol oxidation activity compared with commercial E-Tek, with the same loading of Pt.…”

Low-loading platinum decorated aligned ZnO nanorods and their photocatalytic and electrocatalytic applications

“…remain on the ZnO surface [18]. On the other hand, metal oxides promoted noble metal electrocatalysts is an important research focus in field of electrochemistry [19][20][21][22]. For example, the introduction of metal oxides into Pt and Pd electrocatalysts could significantly promote catalytic activity for ethanol electrooxidation, in which the loading of noble metals could be effectively reduced in practical application [23].…”