Ni-Doped Protonated Layered Titanate/TiO2 Composite with Efficient Photocatalytic Activity for NO    x    Decomposition Reactions

Kanji Saito,Sumio Kato,Masataka Ogasawara,Shota Orikasa,Yoshiyuki Sugahara,Shu Yin,Yusuke Ide,Yusuke Asakura,Elamparuthi Ramasamy

doi:10.1155/2021/8847956

Abstract

A unique structural transformation of a lepidocrocite-type layered titanate, K0.8Ti1.73Li0.27O4, into a rutile-type TiO2 has recently been realized via dilute HCl treatment and subsequent drying at room temperature for producing rutile-nanoparticle-decorated protonated layered titanate exhibiting highly efficient photocatalytic activity. Herein, the authors report synthesis of a lepidocrocite-type layered cesium titanate with nominal compositions of C s 0.7 T i 1.825 ‐ x / 2 N i x □ 0.175 ‐ x / 2 O 4 ( x = 0 , 0.05, 0.1, and 0.35) through solid-state reactions of Cs2CO3, TiO2, and Ni(CH3COO)2·4H2O at different temperatures (600 or 800°C), followed by treatment with dilute HCl and subsequent drying to produce a Ni-doped protonated layered titanate/TiO2 composite. C s 0.7 T i 1.825 ‐ x / 2 N i x □ 0.175 ‐ x / 2 O 4 with an optimized Ni content obtained at a lower temperature was converted into a Ni-doped protonated layered titanate/TiO2 composite to exhibit high photocatalytic activity for NO x decomposition reactions.

Highlights

Fuel production, environmental purification, and fine chemical synthesis using a semiconductor photocatalyst with solar light have attracted tremendous attention for developing sustainable photoenergy conversion processes [1,2,3,4,5]
We selected Nidoped lepidocrocite-type layered cesium titanates with different Ni contents as starting materials, and the effects of the Ni-doping on the photocatalytic activity of the layered cesium titanate after dilute HCl treatment and subsequent drying for NOx decomposition reactions was investigated
Note that the layered cesium titanate with a composition of Cs0:7Ti1:825□0:175O4, which is equivalent to the nominal composition of CTNO (0)_800, has previously been prepared by a solid-state reaction of Cs2CO3 and TiO2 at above 700°C

Summary

Introduction

Environmental purification, and fine chemical synthesis using a semiconductor photocatalyst with solar light have attracted tremendous attention for developing sustainable photoenergy conversion processes [1,2,3,4,5]. Among layered transition metal oxides, lepidocrocitetype layered titanates are characterized by swelling properties as well as compositional versatility [11]. These make them extremely promising candidates for designing highly efficient functional hybrid photocatalysts. Doping of transition metal ions into a TiO2 framework often results in improved photocatalytic activity due to enhanced-charge separation efficiency and/or development of visible-light responsivity [14,15,16,17,18,19]. We selected Nidoped lepidocrocite-type layered cesium titanates with different Ni contents as starting materials, and the effects of the Ni-doping on the photocatalytic activity of the layered cesium titanate after dilute HCl treatment and subsequent drying for NOx decomposition reactions was investigated

Experimental

Results and Discussions

Conclusions