Near-Infrared Light Manipulated Chemoselective Reductions Enabled by an Upconversional Supersandwich Nanostructure

Abstract

Core-satellite is one of the most powerful superstructures since it leads to enhanced or completely new properties through compatible combination of each component. Here we create a novel ceria-based core-shell-satellite supersandwich structure with near-infrared (NIR) light manipulated catalytic activity by integrating the upconversion luminescent and catalytic functionality of CeO2 nanoparticles. Specifically, lanthanide-doped octahedral CeO2 nanoparticles (o-CeO2) are coated with silica layer (o-CeO2@SiO2) to enhance their luminescence intensity. The pH-dependent catalytic active cubic CeO2 nanoparticles (c-CeO2) are then assembled on the surface of o-CeO2@SiO2 to form the supersandwich structure (o-CeO2@SiO2@c-CeO2) following a classic chemical reaction. The upconversion quantum yield of o-CeO2 in this nanostructure can be nearly doubled. Furthermore, under NIR light irradiation, the o-CeO2@SiO2@c-CeO2 supersandwich structure based composite catalyst displays superior catalytic activity in selective reduction of aromatic nitro compounds to corresponding azo compounds, and the composite photocatalyst can be easily recycled for several times without significant loss of catalytic activity. This strategy may serve as a universal method for the construction of multifunctional nanostructures and shed light on the green chemistry for chemical synthesis.

Photoresponsive Biomimetic Protocells for Near-Infrared-Light-Regulated Phototheranostics

“…Photosynthetic-bacteria-inspired studies have attracted increasing attention, challenging researchers to improve the ability to manipulate photons 9,10 and develop more precise and efficient energy transfer pathways. 11,12 The construction of functional nanomaterials that mimic photosynthetic bacteria holds great promise in areas associated with energy conversion, [13][14][15] optoelectronics, 16,17 and nanomedicine. [18][19][20][21] The photosynthesis center of photosynthetic bacteria is located around the light-harvesting antenna formed by self-assembled pigments.…”

Simultaneous quasi-one-dimensional propagation and tuning of upconversion luminescence through waveguide effect

“…In recent years, more and more attention has been paid to the investigations of upconversion mechanism in micro/nanosystems 12 13 14 15 16 , tuning the laser parameters 17 18 19 20 21 , and designing new and more complex upconversion micro/nanostructures 22 23 24 25 to obtain high upconversion efficiency and controlled spectral modulation. For example, core-shell structure successfully devideded space into activator doped region and sensitizer doped region to avoid harmful cross-relaxation 10 .…”

Hairy Fluorescent Nanospheres Based on Polyelectrolyte Brush for Highly Sensitive Determination of Cu(II)

“…The proposed mechanism for TCM is described in Scheme 1. After the addition of EDC and NHS (Scheme 1a), the carboxyl groups of the HNs were transferred into an ester intermediate immediately under the activation of EDC, and in the next step, the ester intermediate was reacted with the amino group on the 5-AF to form a stable amide bond [36][37][38][39][40]. The 5-AF was first coupled to the binding site of the outer layer of the HNs, which reduced the electrostatic property of HNs and the extra 5-AF in the solution was difficult to diffuse into the inner layer of PAA with the electrostatic driving force.…”