Enhancement of the Photoelectrochemical Performance of CuWO₄ Thin Films for Solar Water Splitting by Plasmonic Nanoparticle Functionalization

Abstract

The effect of plasmonic nanoparticles (NPs) on the photoelectrochemical water splitting performance of CuWO 4 is studied here for the first time. CuWO 4 thin films were functionalized with well-defined Au NPs in two composite configurations: with the NPs (I) at the CuWO 4 −electrolyte interface and (II) at the CuWO 4 back contact. In both cases, the incident photon to current conversion efficiency of the film was increased (∼6fold and ∼1.2-fold for configurations I and II (at λ = 390 nm), respectively). Two important advantages of placing the NPs on the CuWO 4 −electrolyte interface are identified: (1) Au NPs, coated with a 2 nm TiO 2 layer, are found to significantly enhance the surface catalysis of the film, decreasing the surface charge recombination from ∼60% to ∼10%, and (2) the NP's near-field can promote additional charge carriers within the space charge layer region, where they undergo field-assisted transport, essentially avoiding recombination. Our study shows that Au NPs, coated with a 2 nm TiO 2 layer, can significantly mitigate the catalytic and optical photoelectrochemical (PEC) limitations of CuWO 4 . An increase from 0.03 to 0.1 mA cm −2 in the water-splitting photocurrent was measured for a 200 nm film under simulated solar irradiation at 1.23 V vs RHE.

Green manufacturing of metallic nanoparticles: a facile and universal approach to scaling up

“…25,28,29 This technique have focused on fabricating NPs using spark ablation (at low frequencies) for a number of new applications (Table S1). 3,6,7,19,25,29,[33][34][35][36][37][38]31,[39][40][41][42][43][44] Note that carrier gases and electrodes determine the particle composition. 25 Although manufacturing electrodes may not be particularly green, the use of recycled metals allows the green manufacturing of NPs.…”

“…In addition, guiding the aerosol NPs to the liquid phase opens numerous possibilities to stabilize them, which, however, results in impurities and expensive/tedious washing procedures. Besides the applications shown in Table S1, nonagglomerated singlet particles have been shown to increase the conversion efficiency of solar cells and photocatalysts for water splitting, 40,41 whereas agglomerated particles have been used to nanofinish a number of antibacterial textiles with high antibacterial activity and good washing durability. 50 With respect to nanocatalysis, we found that the agglomerated NPs at surface can be reconstructed to spheres by annealing.…”

The Role of Size and Dimerization of Decorating Plasmonic Silver Nanoparticles on the Photoelectrochemical Solar Water Splitting Performance of BiVO4 Photoanodes

“…It has been shown that the incident energy absorbed by plasmonic NPs can be transferred to a nearby semiconducting photoelectrode, thereby enhancing its performance . As a result, many noble metal NP/semiconductor systems have been studied to date, in particular to improve the rate of solar photoelectrochemical reactions (e.g., water splitting for hydrogen generation and phenol degradation for water purification) . In many of these studies, the improvement of the semiconductor's performance, upon plasmonic NP functionalization, has been explained by a light trapping mechanism called local electromagnetic field enhancement or light concentration.…”

Photocurrent Response and Progesterone Degradation by Employing WO3 Films Modified with Platinum and Silver Nanoparticles

“…This is probably because the film with two layers is a better anchored semiconductor. Valenti et al [40] reported the enhancement of the photoelectrochemical performance using a CuWO 4 film modified by Au nanoparticle as electrode; this enhancement was attributed to a combination of effects such as plasmon resonance energy transfer (PRET), hot electron injection, and light scattering. WO 3 electrodes with two layers were functionalized with metallic nanoparticles by the photoreduction method.…”