Synthesis of Pt@TiO2@CNTs Hierarchical Structure Catalyst by Atomic Layer Deposition and Their Photocatalytic and Photoelectrochemical Activity

Abstract

Pt@TiO2@CNTs hierarchical structures were prepared by first functionalizing carbon nanotubes (CNTs) with nitric acid at 140 °C. Coating of TiO2 particles on the CNTs at 300 °C was then conducted by atomic layer deposition (ALD). After the TiO2@CNTs structure was fabricated, Pt particles were deposited on the TiO2 surface as co-catalyst by plasma-enhanced ALD. The saturated deposition rates of TiO2 on a-CNTs were 1.5 Å/cycle and 0.4 Å/cycle for substrate-enhanced process and linear process, respectively. The saturated deposition rate of Pt on TiO2 was 0.39 Å/cycle. The photocatalytic activities of Pt@TiO2@CNTs hierarchical structures were higher than those without Pt co-catalyst. The particle size of Pt on TiO2@CNTs was a key factor to determine the efficiency of methylene blue (MB) degradation. The Pt@TiO2@CNTs of 2.41 ± 0.27 nm exhibited the best efficiency of MB degradation.

Precise Definition of a “Monolayer Point” in Polymer Brush Films for Fabricating Highly Coherent TiO2 Thin Films by Vapor-Phase Infiltration

“…TiO2 coatings are widely used in self-cleaning technologies 65 , as an electrode support 66 , as a dielectric medium 67 , and in photocatalysis 68 . ALD grown TiO2 nanofilms have been used in many applications: corrosion protection layers on copper 69 , in high-κ dielectrics, solar cells (perovskite) 70 , carbon nanotubes 71 and composite nanostructures for water splitting to name a few 72 . In this article, a proof-of-concept technique for vapor phase infiltration of covalently grafted polymer brushes to produce wafer-scale TiO2 with high uniformity is demonstrated on Si substrates.…”

Recent Advances in Materials Design Using Atomic Layer Deposition for Energy Applications

“…For example, catalyst deposition method such as impregnation results in particle agglomeration resulting in the formation of metal clusters, while electrodeposition and photodeposition offer much less control over uniform deposition. [ 130 ]…”

Atomic Layer Deposition for the Photoelectrochemical Applications

“…Although metal particles are usually applied to photocathodes from solution by electro‐ or photoelectro‐reduction, ALD was used for the preparation of highly dispersed particles ( Figure a,b) on high‐aspect‐ratio structures such as nanowires. [ 158–160 ] ALD is a promising method to reduce the usage of precious metals, as already one ALD cycle is enough to activate the photocathode, and three cycles were found to uniformly cover the surface with Pt nanoparticles from 0.5 to 3 nm. [ 159 ] Another promising HER catalyst, molybdenum disulfide (MoS 2 ) has only recently become available for ALD deposition, [ 161 ] due to lack of suitable precursors.…”