Lemago Hamsasew Hankebo, Addin Feras Shugaa, Kárajz Dániel Atilla, Igricz Tamás, Parditka Bence, Erdélyi Zoltán, Hessz Dóra, Szilágyi Imre Miklós
Department of Inorganic and Analytical Chemistry, Faculty of Chemical Technology and Biotechnology, Budapest University of Technology and Economics, Műegyetem rkp. 3., H-1111 Budapest, Hungary.
Department of Organic Chemistry and Technology, Faculty of Chemical Technology and Biotechnology, Budapest University of Technology and Economics, Műegyetem rkp. 3., H-1111 Budapest, Hungary.
Nanomaterials (Basel). 2023 Apr 8;13(8):1314. doi: 10.3390/nano13081314.
In comparison to conventional nano-infiltration approaches, the atomic layer deposition (ALD) technology exhibits greater potential in the fabrication of inverse opals (IOs) for photocatalysts. In this study, TiO IO and ultra-thin films of AlO on IO were successfully deposited using thermal or plasma-assisted ALD and vertical layer deposition from a polystyrene (PS) opal template. SEM/EDX, XRD, Raman, TG/DTG/DTA-MS, PL spectroscopy, and UV Vis spectroscopy were used for the characterization of the nanocomposites. The results showed that the highly ordered opal crystal microstructure had a face-centered cubic (FCC) orientation. The proposed annealing temperature efficiently removed the template, leaving the anatase phase IO, which provided a small contraction in the spheres. In comparison to TiO/AlO plasma ALD, TiO/AlO thermal ALD has a better interfacial charge interaction of photoexcited electron-hole pairs in the valence band hole to restrain recombination, resulting in a broad spectrum with a peak in the green region. This was demonstrated by PL. Strong absorption bands were also found in the UV regions, including increased absorption due to slow photons and a narrow optical band gap in the visible region. The results from the photocatalytic activity of the samples show decolorization rates of 35.4%, 24.7%, and 14.8%, for TiO, TiO/AlO thermal, and TiO/AlO plasma IO ALD samples, respectively. Our results showed that ultra-thin amorphous ALD-grown AlO layers have considerable photocatalytic activity. The AlO thin film grown by thermal ALD has a more ordered structure compared to the one prepared by plasma ALD, which explains its higher photocatalytic activity. The declined photocatalytic activity of the combined layers was observed due to the reduced electron tunneling effect resulting from the thinness of AlO.
与传统的纳米渗透方法相比，原子层沉积（ALD）技术在制备用于光催化剂的反蛋白石（IO）方面具有更大的潜力。在本研究中，使用热ALD或等离子体辅助ALD以及从聚苯乙烯（PS）蛋白石模板进行垂直层沉积，成功沉积了TiO IO和IO上的AlO超薄薄膜。使用扫描电子显微镜/能量散射X射线光谱（SEM/EDX）、X射线衍射（XRD）、拉曼光谱、热重/微商热重/差示热分析-质谱（TG/DTG/DTA-MS）、光致发光（PL）光谱和紫外可见光谱对纳米复合材料进行了表征。结果表明，高度有序的蛋白石晶体微观结构具有面心立方（FCC）取向。所提出的退火温度有效地去除了模板，留下了锐钛矿相的IO，这使得球体略有收缩。与TiO/AlO等离子体ALD相比，TiO/AlO热ALD在价带空穴中光激发电子-空穴对具有更好的界面电荷相互作用，以抑制复合，从而产生在绿色区域有峰值的宽光谱。这通过PL得到了证明。在紫外区域也发现了强吸收带，包括由于慢光子导致的吸收增加以及在可见光区域的窄光学带隙。样品光催化活性的结果表明，TiO、TiO/AlO热和TiO/AlO等离子体IO ALD样品分别具有35.4%、24.7%和14.8%的脱色率。我们的结果表明，通过ALD生长的超薄非晶AlO层具有相当大的光催化活性。与通过等离子体ALD制备的AlO薄膜相比，通过热ALD生长的AlO薄膜具有更有序的结构，这解释了其更高的光催化活性。由于AlO薄膜厚度导致电子隧穿效应降低，观察到复合层的光催化活性下降。
