Psathas Pavlos, Zindrou Areti, Papachristodoulou Christina, Boukos Nikos, Deligiannakis Yiannis
Department of Physics, University of Ioannina, 45110 Ioannina, Greece.
Institute of Nanoscience and Nanotechnology (INN), NCSR Demokritos, 15310 Athens, Greece.
Nanomaterials (Basel). 2023 Jan 25;13(3):482. doi: 10.3390/nano13030482.
ABO perovskites offer versatile photoactive nano-templates that can be optimized towards specific technologies, either by means of doping or via heterojunction engineering. SrTiO is a well-studied perovskite photocatalyst, with a highly reducing conduction-band edge. Herein we present a Double-Nozzle Flame Spray Pyrolysis (DN-FSP) technology for the synthesis of high crystallinity SrTiO nanoparticles with controlled La-doping in tandem with SrTiO/CuO-heterojunction formation. So-produced La:SrTiO/CuO nanocatalysts were optimized for photocatalysis of HO/CHOH mixtures by varying the La-doping level in the range from 0.25 to 0.9%. We find that, in absence of CuO, the 0.9La:SrTiO material achieved maximal efficient photocatalytic H production, i.e., 12 mmol g h. Introduction of CuO on La:SrTiO enhanced selective production of methane CH. The optimized 0.25La:SrTiO/0.5%CuO catalyst achieved photocatalytic CH production of 1.5 mmol g h. Based on XRD, XRF, XPS, BET, and UV-Vis/DRS data, we discuss the photophysical basis of these trends and attribute them to the effect of La atoms in the SrTiO lattice regarding the H-production, plus the effect of interfacial CuO on the promotion of CH production. Technology-wise this work is among the first to exemplify the potential of DN-FSP for scalable production of complex nanomaterials such as La:SrTiO/CuO with a diligent control of doping and heterojunction in a single-step synthesis.
ABO钙钛矿提供了通用的光活性纳米模板，可通过掺杂或异质结工程针对特定技术进行优化。SrTiO是一种经过充分研究的钙钛矿光催化剂，具有高度还原的导带边缘。在此，我们展示了一种双喷嘴火焰喷雾热解（DN-FSP）技术，用于合成具有可控La掺杂并同时形成SrTiO/CuO异质结的高结晶度SrTiO纳米颗粒。通过在0.25%至0.9%的范围内改变La掺杂水平，如此制备的La:SrTiO/CuO纳米催化剂针对HO/CHOH混合物的光催化进行了优化。我们发现，在没有CuO的情况下，0.9La:SrTiO材料实现了最大效率的光催化产氢，即12 mmol g h。在La:SrTiO上引入CuO增强了甲烷CH的选择性生成。优化后的0.25La:SrTiO/0.5%CuO催化剂实现了1.5 mmol g h的光催化CH生成。基于XRD、XRF、XPS、BET和UV-Vis/DRS数据，我们讨论了这些趋势的光物理基础，并将其归因于SrTiO晶格中La原子对产氢的影响，以及界面CuO对促进CH生成的影响。从技术角度来看，这项工作是首批例证DN-FSP在一步合成中精确控制掺杂和异质结以可扩展生产复杂纳米材料（如La:SrTiO/CuO）潜力的工作之一。
