Enhanced Photocatalytic Hydrogen Evolution Over CaTi1−x Zr x O3 Composites Synthesized by Polymerized Complex Method

Abstract

The solid solution of CaTi 1-x Zr x O 3 (x = 0-0.15) was successfully synthesized by the polymerized complex (PC) method. This study has exhibited the advantage of the PC method to prepare a highly active CaTiO 3 compared with the conventional solid-state reaction (SSR) method. More importantly, further improvement in phase purity and large surface area was achieved by the doping of Zr 4+ , leading to remarkable enhancement of photocatalytic activities compared to pure CaTiO 3 . The quantum yield for H 2 evolution over the most active photocatalyst, Pt (1.0 wt%)/CaTi 0.93 Zr 0.07 O 3 , was 1.91% and 13.3% in photoreactions from pure water and aqueous ethanol solution, respectively for 0.1 g photocatalyst, which was about 3.3 and 2.5 times compared to that of PCderived CaTiO 3 .

Effects of Cocatalyst and Calcination Temperature on Photocatalytic Hydrogen Evolution Over BaTi4O9 Powder Synthesized by the Polymerized Complex Method

“…TiO 2 -based compounds have been extensively investigated as efficient photocatalysts for photodecomposition of water under UV irradiations [1][2][3][4][5]. The compounds of barium titanates are of great importance in materials science due to their attractive ferroelectric and dielectric properties.…”

CaTaO2N–CaZrO3 solid solution: Band-structure engineering and visible-light-driven photocatalytic hydrogen production

“…The apparent particle size gradually increased with the decrease of x, in consistence with the calculated crystallite size derived from the XRD data. Moreover, it can be seen from the SEM images that the primary particles turned out to be dense and uniform, as may be attributed to the synthetic method (PC method) allowing the sufficient contact of reagents at a molecular level [22]. In addition, piled pores with random diameters could be identified from the images of the samples.…”

“…Besides, It is reported that CaTi 1Àx Zr x O 3 had enhanced photocatalytic activity compared to pure CaTiO 3 , for the improvement in phase purity and large surface area achieved by the doping of Zr 4þ [22]. Analogously, based on the similar crystallographic parameters of CaTaO 2 N and CaZrO 3 and the little discrepancy of ion radiuses (Ta 5þ : 0.70 Å ; Zr 4þ : 0.79 Å ) [23], it is reasonable to construct a CaTa x Zr (1Àx) O (3Àx) N x solid solution with adjustable band gap and band edge.…”

“…In this study, a series of oxide precursors of CaTa x Zr (1Àx) O (3Àx) N x (x ¼ 1.0, 0.8, 0.6, 0.4, 0.2 or 0.0) were prepared by the polymerized complex (PC) method [25] which had a great advantage over conventional solid-state reaction for the mixing of elements at a molecular level [22]. Among the synthesized solid solutions, CaTa 0.8 Zr 0.2 O 2.2 N 0.8 showed best hydrogen production in formic acid aqueous solution.…”

Preparation and Photocatalytic Activity of (Cu0.94La0.06)2SnO4 Nanocomposite Photocatalyst Under Simulated Sunlight

“…Therefore, developing new visible-light photocatalysts is necessary to extend the absorption wavelength range into the visible-light region [7]. A number of studies related to the photocatalytic activity of coupled semiconductor photocatalysts, including Nd 2 InTaO 7 [8], In 1-x M x TaO 4 [9], (CuIn) x Zn 2(1-x) S 2 [10], CaTi 1-x Zr x O 3 [11], and CuO/ SnO 2 [12], have recently been conducted. These semiconductor photocatalysts increase the photocatalytic efficiency by increasing the charge separation and extending the photo-responding range.…”