Our goal is to perform fundamental mechanistic studies of electronic interactions at molecule-semiconductor (MO) nanoparticle interfaces through an interdisciplinary effort that combines synthetic design and spectroscopic characterization.
Our approach is to use rigid linkers to fix the position of chromophoric groups (also called sensitizers or dyes) relative to the nanoparticle’s surface. The nanoparticles of interest are crystalline metal oxide materials, usually anatase TiO2, with controlled diameters (~ 2 to 20 nm) that are prepared by sol-gel processing techniques and cast into thin films on conductive glass or other substrates following known procedures. We also study colloidal diluted solutions. The rigid linkers carrying the chromophore are anchored to the metal oxide films through carboxylic (COOH) or phosphonic acid (P(=O)(OH)2) groups.
A few examples of the many types of anchor-linker-chromophore systems that we studied are shown in figure below.
Main current projects:
· The development of linker-dye models varying in length and structure for fundamental electron transfer studies, for instance distance dependence (with Prof. Piotr Piotrowiak)
· The study of the electronic communication between molecular components (molecular, supramolecular) and the substrate (semiconductor)
· To tune and improve the dye properties (absorption range, extinction coefficient etc..) by means of the linker
· The prevention of the aggregation of dye molecules on the semiconductor surface by the linker design 
· The study of the chemical bond (IR, Raman, theoretical calculations) between the anchoring group and the MO surface to improve and control the functionalization of MO surfaces.
· The development of multichromophoric linkers for improved efficiencies
· The functionalization of Prof. Yicheng Lu’s ZnO nanotips
