Quantifying Visible-Light-Induced Electron Transfer Properties of Single Dye-Sensitized ZnO Entity for Water Splitting

Abstract

Quantifying the photoinduced electron transfer properties of a single entity is of paramount importance for clarifying the link between the photoelectrochemical performance and the specific properties of an individual. Here, we successfully monitored the photoelectrochemical behavior of a single dye-sensitized ZnO entity on a Au ultramicroelectrode with different TiO film thicknesses. Due to a trap-limited electron diffusion in TiO film, a sub-millisecond photocurrent transient was observed for an individual N719@ZnO associated with single-particle photocatalytic water splitting. Furthermore, a Monte Carlo random walk numerical simulation model was developed to simulate the photoinjected electron transport dynamics and recombination in a nanoparticulate TiO film. Our approach allowed the photocatalytic properties of N719 at the single-molecule level to be quantified, and electron diffusivity and electron collection efficiency as a function of the film thickness were estimated by simulation analyses. Excellent agreement was obtained between the experimental results and theoretical simulations, indicating that the underlying photoinduced electron transfer processes can be reliably explored.

Effects of Instrumental Filters on Electrochemical Measurement of Single‐Nanoparticle Collision Dynamics

“…While the calculated results above (Figures and ) suggest that one should strive for the highest frequency filter, in experimental measurements, the response time of instrumental circuitry (which acts an amplifier) and the noise associated with a measurement must be considered. Moreover, in a real‐world instrumental measurement, the time‐response of the entire instrumental circuitry, the electrode leads, the resistance of the solution and capacitance of the double‐layer all act as a filter and should be considered as such ,,,. While noise from environmental sources should be minimized by the use of a Faraday cage and proper grounding, noise associated with physical processes and the internal circuitry of the instrument (e. g., thermal noise) cannot be completely eliminated.…”

Nanoceutical Fabric Prevents COVID-19 Spread through Expelled Respiratory Droplets: A Combined Computational, Spectroscopic and Anti-microbial Study

“…This could well be interpreted by the existence of several luminescent centers (originated from the presence of conjugated chromophores of various origins) in the cellulose [67]. One possible mechanism behind the observed decrease in the fluorescence lifetime of ZnO NF decorated cellulose could be due to the photoinduced electron transfer (PET) from the LUMO level of the low energy excitation centers (near red end) of cellulose to the conduction band of ZnO, resulting in the luminescence quenching of cellulose [69]. Presence of a very fast component (i.e., 25 ps) in the excited state lifetime decay of ZnO NF decorated cellulose further supports our conjecture.…”

Semiconducting Nanoparticles: Single Entity Electrochemistry and Photoelectrochemistry

“…This powerful electrochemical technique has found much strength in giving insights into the fundamental study of nanoparticles: not only the basic particle characterization (e.g. sizing, concentration, chemical identity, agglomeration/aggregation state, porosity) ( Zhou et al, 2011 ; Stuart et al, 2012 ; Tschulik et al, 2014 ; Jiao et al, 2017 ; Li et al, 2019 ), but also in-depth understanding at single-particle levels for the mechanisms and dynamics of (photo) electrochemical processes of interest ( Xiao and Bard, 2007 ; Bard et al, 2010 ; Fernando et al, 2013 ; Li et al, 2016 ; Ma et al, 2018 ; Peng et al, 2018 ).…”

“…Moreover, the mechanistic investigation on (photo) electrochemistry of individual NPs will contribute to understand and ultimately control the charge transfer at nanoscale. Even though several reports and reviews have summarised single SC photo-electrochemistry ( Peng et al, 2018 ; Barakoti et al (2016) ; Ma et al, 2018 ; Alpuche-Aviles et al, 2019 ; Wang et al, 2019 ; Wang et al, 2020 ), their electrochemical redox behavior and electro-catalytical activities were not comprehensively included. Therefore, our distinct aim of the mini review is to facilitate insight into both the electrochemistry and photoelectrochemistry of single semiconducting nanoparticles.…”