Photodegradation of Orange II under Visible Light Using Cu–Ni/TiO₂: Influence of Cu:Ni Mass Composition, Preparation, and Calcination Temperature

Abstract

Bimetallic Cu−Ni/TiO 2 photocatalysts were prepared at different temperatures with varying Cu:Ni mass compositions. The photocatalysts were further calcined at selected temperatures. Characterization procedures were carried out on the photocatalysts to understand the correlation between the photocatalytic activity and the physicochemical and morphological properties. Results from the XRD, FESEM-EDX mapping, and HRTEM analyses were in favor of the metal particles existing in the form of well-dispersed oxides on TiO 2 surface. The surface area of the photocatalysts was almost similar to the bare TiO 2 ∼43 m 2 g −1 except for 1Cu:9Ni-200-b observed with a higher surface area (53.8 m 2 g −1 ) as compared to other photocatalysts. The photocatalyst performance of the bimetallic system is promising as compared to bare TiO 2 and the monometallic photocatalysts. Results for photodegradation studies showed that 1:9 Cu:Ni mass composition was observed with 100% Orange II removal as compared to other Cu:Ni mass compositions. The 1Cu:9Ni-200-a photocatalyst prepared at lower temperature (8−10 °C) displayed 100% Orange II decolorization as compared to 1Cu:9Ni-200-b (prepared at higher temperature of 25 °C) with 65.1% dye removal. Although the results from UV−vis spectra showed the disappearance of the visible band (indicating 100% Orange II removal), TOC analysis indicated the presence of organic compounds derived from the dye degradation process. Therefore, longer irradiation time is required to break the chromophore groups in the degradation intermediates to obtain 100% TOC removal.

Cu and Zr surface sites in photocatalytic activity of TiO2 nanoparticles: The effect of Zr distribution

“…A synergistic effect is possible if two different transition metal elements are co-loaded to TiO 2 [18]. The positive effects of nickel [19] and silver [20] containing species for copper modified Aeroxide ® Degussa P25 titanium dioxide (P25) were observed. Commercial Aeroxide ® Degussa P25 is known as a mixed phase TiO 2 benchmark with high UV-light activity.…”

Piezotronic-effect-enhanced Ag2S/ZnO photocatalyst for organic dye degradation

“…[18][19][20][21] Transition metals, such as Cu, Co, and Ni, have been investigated in an attempt to replace noble metals. [22][23][24] In semiconductor/semiconductor hybrid photocatalysts, metal oxides and suldes have been extensively applied to construct heterojunctions/interfaces that can effectively facilitate the spatial separation of photoexcited electron-hole pairs using suitable band alignment. In particular, for type II heterojunctions/interfaces, photoexcited electrons tend to transfer from the semiconductor with a narrower band gap to that with a wider band gap, while photoexcited holes oen transfer in the opposite direction due to the relative positions of the valence band (VB) and conduction band (CB).…”

Study on the degradation mechanism and pathway of benzene dye intermediate 4-methoxy-2-nitroaniline via multiple methods in Fenton oxidation process

“…23,24 This is based on their strong oxidation performance and a wide range of applications of AOT. [25][26][27][28][29] For AOT, electrochemical incineration, 30 microwave radiation, 5 photocatalysis, 31,32 and other Fenton methods 2,4 have been also used to treat BDIs wastewater effectively. However, the above methods have some limitations in practical application.…”