Synergistic Effect of Plasmonic Gold Nanoparticles Decorated Carbon Nanotubes in Quantum Dots/TiO₂ for Optoelectronic Devices

Abstract

Here, a facile approach to enhance the performance of solar-driven photoelectrochemical (PEC) water splitting is described by means of the synergistic effects of a hybrid network of plasmonic Au nanoparticles (NPs) decorated on multiwalled carbon nanotubes (CNTs). The device based on TiO 2-Au:CNTs hybrid network sensitized with colloidal CdSe/(CdSe x S 1−x) 5 /(CdS) 1 core/alloyed shell quantum dots (QDs) yields a saturated photocurrent density of 16.10 ± 0.10 mA cm −2 [at 1.0 V vs reversible hydrogen electrode (RHE)] under 1 sun illumination (AM 1.5G, 100 mW cm −2), which is ≈26% higher than the control device. The in-depth mechanism behind this significant improvement is revealed through a combined experimental and theoretical analysis for QDs/TiO 2-Au:CNTs hybrid network and demonstrates the multifaceted impact of plasmonic Au NPs and CNTs: i) hot-electron injection from Au NPs into CNTs and TiO 2 ; ii) near-field enhancement of the QDs absorption and carrier generation/separation processes by the plasmonic Au NPs; iii) enhanced photoinjected electron transport due to the highly directional pathways offered by CNTs. These results provide fundamental insights on the properties of QDs/TiO 2-Au:CNTs hybrid network, and highlights the possibility to improve the performance of other solar technologies.

Quantum Dots‐Based Photoelectrochemical Hydrogen Evolution from Water Splitting

“…An effective strategy to alleviate this problem is to combine the supporting semiconductors (such as TiO 2 ) with low‐resistive materials as a direct pathway to guide the photogenerated electrons (Figure 3b), where faster photoexcited electron transfer from the semiconductor to the liquid/solid interface and consequent high photocurrent were achieved, examples including TiO 2 combined with a metal–organic framework (MOF), [ 80b ] 1D graphene nanoribbon networks, [ 84 ] graphene, [ 88 ] multiwalled carbon nanotubes (MWCNTs), [ 89 ] and Au‐nanoparticle‐decorated MWCNTs. [ 90 ] Another effective solution is to facilitate charge transfer without encountering grain boundaries by tuning the morphologies of framework semiconductors (e.g., TiO 2 ) as 1D nanostructures, such as nanorods, [ 45a,d,47,91 ] nanotubes, [ 92 ] and nanowires, [ 36b,45b,c,e,93 ] while the bottleneck is their limited specific surface area for PEC reactions. To maintain the specific surface area and high electron transport simultaneously, a hierarchical structure was fabricated by growing ZnO nanowires on silicon microwires with a hydrothermal method, [ 45f ] as shown in Figure 3c.…”

Phosphorus and Selenium Co‐Doped WO3 Nanoparticles for Interface Modification and Photovoltaic Properties Enhancement of Monolayer Planar Silicon/PEDOT:PSS Hybrid Solar Cells

“…As shown in Figure 1b, the lattice spacings of 3.75 and 3.39 nm were ascribed to the (002) and (020) planes of P/Se–WO x nanoparticles, respectively (upper right inset of Figure 1b). [ 22,29,30 ] This corresponds to the X‐ray diffraction (XRD) results in Figure S1, Supporting Information.…”

Ni Foam Supported TiO2 Nanorod Arrays with CdS Branches: Type II and Z‐Scheme Mechanisms Coexisted Monolithic Catalyst Film for Improved Photocatalytic H2 Production

“…[ 22–24 ] Up to now, almost all the reported TiO 2 nanoarrays are grown on these two types of substrates: metal foil or conductive glass. Based on these, various improvement strategies have been carried out to pursue their desired energy storage and conversion properties such as doping foreign elements, [ 25 ] formulating hybrid composited structure, [ 17,26,27 ] loading efficient cocatalysts, [ 28,29 ] constructing advantaged structures and morphologies, [ 4,30 ] adjusting the exposing crystalline surface, surface sensitization, etc. However, the 2D plane structure of metal foil or glass substrate limits the content and mass transfer performance of monolayer 1D TiO 2 catalysts, which may fundamentally reduce the energy collection and conversion efficiency of such materials.…”