论文标题
用Pt掺杂的镁含量,用于光催化氢的进化
Magneli phases doped with Pt for photocatalytic hydrogen evolution
论文作者
论文摘要
已定义的定位化钛氧化物(Ti $ _x $ o $ $ _ {2x-1} $,$ 3 <x <10 $)称为Magneli阶段,主要是因为其异常的高电导率和类似金属的行为而进行了研究。在光催化中,据报道,含有钛颗粒的镁相可提供有利的电荷分离,从而提高了反应效率。在当前的工作中,我们描述了含镁的混合相纳米颗粒的一步合成,该纳米颗粒含有直接集成的少量PT。对于H $ _2 $ Evolution的相位优化的纳米颗粒(仅包含几百ppm pt)是非常有效的光催化剂(它们提供的h $ _2 $进化比普通疗法酶高出50-100倍,而普通的解剖酶载有相似量的PT)。这些光催化剂是在结合热壁反应器的设置中合成的,该反应器用于Tiox合成与产生PT纳米颗粒的火花发电机。不同的反应器温度导致解剖酶和木质相之间的各种相比。使用XRD,HRTEM,XPS和EPR光谱以及ICP -OES分析来表征钛纳米颗粒(约24-53 nm)。以900 $^\ CIRC $ C制备的最佳光催化剂(由32%剖析酶,11%金红石和57%的Magneli相结合的混合相颗粒组成,加载了290 ppm的PPM)可以提供光催化H $ _2 $ _2 $的演化率。 5432 Micromol H $^{ - 1} g $^{ - 1} $用于UV和CA。 1670 Micromol H $^{ - 1} g $^{ - 1} $用于AM1.5照明。对于转换为更高量的木尼相(1000 $^\ circ $ c和1100 $^\ circ $ c)的粉末,观察到光催化H $ _2 $发电活动的急剧损失。因此,在最佳条件下,高光催化效率归因于与常规的PT/Aratase连接相比,Magneli Titania和PT的多障碍之间的有效协同作用。
Defined substoichiometric titanium oxides (Ti$_x$O$_{2x-1}$ with $3 < x < 10$) called Magneli phases have been investigated mostly for their unusual high conductivity and metal-like behavior. In photocatalysis, Magneli phase containing titania particles have been reported to provide favorable charge separation resulting in enhanced reaction efficiency. In the current work we describe a one-step synthesis of Magneli-containing mixed phase nanoparticles that carry directly integrated minute amounts of Pt. Phase optimized nanoparticles that contain only a few hundred ppm Pt are very effective photocatalysts for H$_2$ evolution (they provide a 50-100 times higher H$_2$ evolution than plain anatase loaded with a similar amount of Pt). These photocatalysts are synthesized in a setup combining a hot-wall reactor that is used for TiOx synthesis with a spark generator producing Pt nanoparticles. Different reactor temperatures result in various phase ratios between anatase and Magneli phases. The titania nanoparticles (ca. 24 - 53 nm) were characterized using XRD, HRTEM, XPS and EPR spectra as well as ICP-OES analysis. The best photocatalyst prepared at 900$^\circ$C (which consists of mixed phase particles of 32% anatase, 11% rutile and 57% Magneli phases loaded with 290 ppm of Pt) can provide a photocatalytic H$_2$ evolution rate of ca. 5432 micromol h$^{-1} g$^{-1}$ for UV and ca. 1670 micromol h$^{-1} g$^{-1}$ for AM1.5 illumination. For powders converted to higher amounts of Magneli phases (1000$^\circ$C and 1100$^\circ$C), a drastic loss of the photocatalytic H$_2$ generation activity is observed. Thus, the high photocatalytic efficiency under best conditions is ascribed to an effective synergy between multi-junctions of Magneli titania and Pt that enable a much more effective charge separation and reaction than conventional Pt/anatase junctions.