Incorporation of ultrafine TiO2/CdS heterojunction in dendritic porphyrins mesoporous silica nanospheres for efficient photocatalytic oxidation of styrene

In this paper, a novel host–guest assembly strategy is developed to incorporate TiO 2 nanoparticles and CdS quantum dots (CdS QDs) into the photoactive dendritic porphyrins mesoporous silica nanospheres (DPMSN) channels for establishing heterojunctions nanoreactors (designated as DPMSTNC). The well-defined dendritic architecture facilitates the high dispersion of TiO 2 /CdS heterojunctions within the DPMSN matrix, effectively maximizing the interfacial contact area between the heterojunction components and the cobalt porphyrin framework. Crucially, the synergistic interplay of cobalt porphyrins incorporated in the silica framework and the ultra-small TiO 2 /CdS heterojunction in the dendritic channels promotes efficient charge transfer and separation in the nanoreactor. The optimized DPMSTNC nanoreactor exhibits excellent catalytic performance with a conversion of 96.0 % and a selectivity of 92.0 % in styrene oxidation, which significantly surpasses that of single-component catalysts and simple composite heterostructure catalysts. This nanoreactor design strategy, which combines spatially confined heterojunctions with photoactive porous frameworks, provides a novel and versatile platform for developing high-efficiency photocatalytic systems through precise nanoarchitectural control.