Engineering the outermost layers of TiO₂ nanoparticles using in situ Mg doping in a flame aerosol reactor

Abstract

Titanium dioxide nanoparticles with disordered outermost layer sturctures have significantly enhanced light absorption and photocatalytic properties and thus receiving enhanced attention in recent years. Engineering the outermost layers using in situ magnesium doping to tailor the band‐edge of TiO2 nanoparticles was achieved via a flame aerosol reactor. The distribution of doped elements in nanoparticles could be controlled in a high temperature flame process, and which could be predicted by the comparison of different characteristic time scales, such as reaction time, coagulation time, and sintering time is proposed. In situ magnesium doping on the outermost layers effectively tailored the conduction band and electron structure of the TiO2 nanoparticles, and simultaneously improved the maximum photocurrent as well as the maximum photovoltage in dye‐sensitized solar cells. These improvements were largely attributed to red‐shifted light absorption, and rapid photoelectron injection into the conduction band. © 2016 American Institute of Chemical Engineers AIChE J, 63: 870–880, 2017

Optimizing SnO2−x/Fe2O3 Hetero‐Nanocrystals Toward Rapid and Highly Reversible Lithium Storage

“…As shown in Figure 1d Spray combustion is applied to controllably synthesize highdispersion SnO 2−x /Fe 2 O 3−y hetero-nanocrystals in microseconds, which mainly relies on the shearing force to spray the precursors solution into the flame reaction zone with ultrafast decomposition. [25] The formation process of the optimized SnO 2−x /Fe 2 O 3 is schematically shown in Figure 2a. The highpressure gas mixture of H 2 \O 2 \Air are mixed in the control unit and sprayed out through a homemade nozzle.…”

Mini Review on Gas-Phase Synthesis for Energy Nanomaterials

“…Bubenhofer et al (2012) presented PbS-TiO 2 heterojunction nanoparticles by reducing FSP for solar cells. Hu et al (2017) tailored the band-edge of TiO 2 nanoparticle using in situ magnesium doping in a FLAR. The DCCS efficiency improved by about 5.8% due to a negatively shifted band-edge and the upward shifted quasi-Fermi level resulting from Mg-doping.…”

“…Schematic of conduction band and quasi-Fermi level movements in Mg 2+ -doped TiO 2 . (Reprinted with permission from Hu et al Copyright 2017 AIChE. )…”

Influence of flame-generated ions on the simultaneous charging and coagulation of nanoparticles during combustion

“…Combustion is a major source of particulate matter (PM) generation (Biswas and Wu 2005). The precise control of aerosol formation during combustion is equally crucial for both the applications of flame-generated particles (Liu et al 2015;Hu et al 2016;Li et al 2016b) and their environmental implications (Wang et al 2013;Li et al 2016a). However, a detailed understanding of the particle dynamics in flames is lacking due to the fast reaction rate of combustion, making it difficult to control the particle formation and growth processes.…”