Photoelectrochemical Studies on CdS/Poly Ethyl-Aniline Interfaces

Abstract

An inorganic/organic/interface (IOI) consisting of CdS/poly ethyl aniline (PEA) assemblies was subjected to photoelectrochemical studies in nanoparticle suspensions and in thin solid film forms . The effects that PEA modifiers have on the photoelectrochemical behavior of the IOI were investigated using [Fe(CN) 6 ] 4-as a photoactive hydrated electron donor agent. Results show that the adsorption process of [Fe (CN) 6 ] 3-(the photolysis product) controls the photoactivity outcome of IOI assemblies. CdS/PEA shows lower heterogeneous photochemical response than native CdS. Native CdS amorphous nanoparticles adsorb more [Fe(CN) 6 ] 3-with a very steady adsorption/desorption process than the CdS/PEA. The interface activities were explained by analyzing the IOI junction's properties such as electron affinity, work function and hole/electrons barrier heights. The lower hole barrier height versus electron barrier height suggests that charge injection is mediated at the IOI interface through hole transfer. The aqueous nano systems retained moderate stability as indicated by the reproducibility of their photocatalytic activities. Both [Fe(CN) 6 ] 4-and PEA contributed to the stability of native CdS surfaces.

Photoelectrochemical Studies on High Specific Capacitance-Photoactive Interfaces Based on Poly 3,4- Ethylenedioxythiophene/Metal Oxides Assemblies

“…Peak A in Figure 6 is the result of total electrochemical reduction of any [Fe(CN) 6 ] 3− shown in the following photoreaction: The number of photons consumed in this photoreaction can be calculated from the integration of the green zone portion in Figure 6. The mechanism of the reaction in Equation 7has been previously discussed [18]. The data listed in Table 2 clearly show that modified TiO 2 with PEDOT was more efficient than in the process of photoreduction of [Fe(CN) 6 ] 3− on native TiO 2 .…”

“…The theory of the photolysis of aqueous [Fe(CN) 6 ] 4− has been discussed elsewhere [18]. In this study, aqueous suspensions of pure TiO 2 and TiO 2 surface-modified with PEDOT in 0.2 M phosphate buffer at pH 6 containing 0.010 M [Fe(CN) 6 ] 4− were subject to the photolysis process.…”