CdS/TiO2 1/n (n = 4, 8 and 32) composite materials are synthesized maintaining constant the amount of CdS and varying the amount of TiO2. XRD, HRTEM, FESEM/EDS analysis point out that both CdS and TiO2 maintain their original crystalline structure but are in intimate interconnection. BET and porosity analysis evidence that SSA are similar in all cases, with CdS/TiO2 1/32 showing also mesoporosity in addition to microporosity. Microcalorimetric analysis demonstrates that all composite materials are hydrophilic in nature, but CdS/TiO2 1/8 and CdS/TiO2 1/32 show a larger number of sites interacting with water molecules. Photoelectrochemical investigation showed that the intimate contact between CdS and TiO2, allows electrons injection from CdS to TiO2 increasing the lifetimes of separated charges. Cyclic voltammetry experiments demonstrate that both CdS and TiO2 can reduce benzaldehyde with electrons residing in their conduction bands, whereas the surface features of the composite favor the photocatalyst/substrate interactions. The understanding of how to combine energetics, heterojunctions, morphology and surface characteristics of the photoactive materials opens the way towards an efficient design of CdS/TiO2 1/n composite systems, which show significant advances over the use of the two separate components: i) the presence of TiO2 modifies the characteristics of the CdS surface, favouring the approach of organic molecules, such as benzaldehyde and its reaction intermediates; ii) CdS, activated by irradiation with visible light, can inject electrons onto TiO2 which is in turn activated without using UV light. This paves the way for the application of more sustainable experimental conditions to achieve reductive transformations in the presence of TiO2.
A physico-chemical insight into the benzaldehyde reduction mechanism catalysed by CdS/TiO2 composites activated by visible light
Martina MilaniInvestigation
;Edoardo MarchiniInvestigation
;Alessandra MolinariWriting – Review & Editing
2026
Abstract
CdS/TiO2 1/n (n = 4, 8 and 32) composite materials are synthesized maintaining constant the amount of CdS and varying the amount of TiO2. XRD, HRTEM, FESEM/EDS analysis point out that both CdS and TiO2 maintain their original crystalline structure but are in intimate interconnection. BET and porosity analysis evidence that SSA are similar in all cases, with CdS/TiO2 1/32 showing also mesoporosity in addition to microporosity. Microcalorimetric analysis demonstrates that all composite materials are hydrophilic in nature, but CdS/TiO2 1/8 and CdS/TiO2 1/32 show a larger number of sites interacting with water molecules. Photoelectrochemical investigation showed that the intimate contact between CdS and TiO2, allows electrons injection from CdS to TiO2 increasing the lifetimes of separated charges. Cyclic voltammetry experiments demonstrate that both CdS and TiO2 can reduce benzaldehyde with electrons residing in their conduction bands, whereas the surface features of the composite favor the photocatalyst/substrate interactions. The understanding of how to combine energetics, heterojunctions, morphology and surface characteristics of the photoactive materials opens the way towards an efficient design of CdS/TiO2 1/n composite systems, which show significant advances over the use of the two separate components: i) the presence of TiO2 modifies the characteristics of the CdS surface, favouring the approach of organic molecules, such as benzaldehyde and its reaction intermediates; ii) CdS, activated by irradiation with visible light, can inject electrons onto TiO2 which is in turn activated without using UV light. This paves the way for the application of more sustainable experimental conditions to achieve reductive transformations in the presence of TiO2.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
