Spatially Resolved Optical Spectroscopic Measurements with Simultaneous Photoelectrochemical Mapping Using Scanning Electrochemical Probe Microscopy.
Emmanuel Mena-MorcilloJoshua van der ZalmAicheng ChenPublished in: The journal of physical chemistry letters (2023)
A deep understanding of the properties of semiconductor films at the micro-/nanoscale level is fundamental toward designing effective photoelectrocatalysts. Here, we integrated spatially resolved optical spectroscopy (SR-OS) with scanning photoelectrochemical microscopy (SPECM) to collect UV/vis spectra and quantify photocurrents of localized sites on a nanostructured BiVO 4 thin film. Direct measurement of absorbance allowed for the determination of band gap energy at each location. Absorbance and photocurrent maps were obtained and used to investigate heterogeneities on the films. Scanning electrochemical cell microscopy (SECCM) was also coupled with SR-OS to acquire quantitative photoelectrochemical data at the FTO/BiVO 4 film interface, revealing higher photocurrents at the boundary regions. As a droplet-based technique, SECCM was employed to estimate the wetted area by measuring the maximum height of droplet stretch at each point, allowing for the calculation of photocurrent density. This novel approach provides an advantageous mean to correlate localized photocatalytic activities and band gap energies.
Keyphrases
- high resolution
- visible light
- label free
- room temperature
- single cell
- molecularly imprinted
- high speed
- ionic liquid
- quantum dots
- high throughput
- gold nanoparticles
- mass spectrometry
- density functional theory
- atomic force microscopy
- body mass index
- tandem mass spectrometry
- single molecule
- electronic health record
- electron microscopy
- sensitive detection
- cell therapy
- solid phase extraction
- reduced graphene oxide
- big data
- living cells
- machine learning
- carbon nanotubes
- mesenchymal stem cells
- bone marrow
- artificial intelligence