Photocatalytic Removal of Methyl Orange Azo Dye with Simultaneous Hydrogen Production Using Ru-modified ZnO Photocatalyst

Abstract

The aim of this work is to demonstrate the effectiveness of the photocatalytic process in the Methyl Orange azo dye degradation and simultaneous H2 production by using ZnO doped with ruthenium. Ru-modified ZnO photocatalysts were prepared by precipitation method and were characterized by different techniques (XRF, Raman, XRD, N2 adsorption at −196 °C, and UV–vis DRS). The experiments were carried out in a pyrex cylindrical reactor equipped with a nitrogen distributor device and irradiated by four UV lamps with the main wavelength emission at 365 nm. Different Ru amounts (from 0.10 to 0.50 mol%) were tested in order to establish the optimal amount of the metal to be used for the ZnO doping. The photocatalytic activity was evaluated both in terms of Methyl Orange removal and hydrogen production. The experimental results showed that the best activity, both in terms of H2 production and Methyl Orange degradation, was obtained with the Ru-modified ZnO photocatalyst at 0.25 mol% Ru loading. In particular, after four hours of UV irradiation time, the discoloration and mineralization degree were equal to 83% and 78%, with a simultaneous hydrogen production of 1216 µmol L−1. This result demonstrates the ability of the photocatalytic process to valorize a dye present in wastewater, managing to obtain a hydrogen production comparable with the data present in the literature today in the presence of other sacrificial substances.

TiO2 Photocatalysis for the Transformation of Aromatic Water Pollutants into Fuels

“…A wide variety of photocatalysts was designed to achieve the goal of the dualfunctional photocatalysis technology; simultaneous H 2 production and wastewater purification by the degradation of the persistent dyes [38,39,189,[259][260][261][262]. The production of hydrogen with a simultaneous degradation of azo dye solution (commercial name Acid Orange 7; AO7) using the well-known photocatalyst Pt/TiO 2 suspensions was examined by Patsoura [261] under UV-vis light.…”

Optical, morphological and photocatalytic properties of biobased tractable films of chitosan/donor-acceptor polymer blends

“…In spite of this, interesting advantages can be envisioned for these biobased films e.g., this type of catalyst is entirely constituted of compounds of an organic nature; hence, they can be considered to be "all-polymer" catalysts. Additionally, biobased films acting as catalysts would help replace the use of inorganic, expensive and potentially toxic catalysts based on Rh, Au, Pt, Ir and Ru that commonly display similar or even lower reduction rates after a few cycles of use (Aghakhaninejad, Rahimi, & Zargari, 2018;Chaker, Chérif-Aouali, Khaoulani, Bengueddach, & Fourmentin, 2016;Dhanalakshmi, Saravanakumar, Prabavathi, & Muthuraj, 2020;Masoud, Nourbakhsh, & Hassanzadeh-Tabrizi, 2017;Vaiano & Iervolino, 2019;Zhang et al, 2019). It is well-known that the duration, versatility, and performance of a catalyst are crucial aspects, especially for light-driven chemical reactions of technological importance.…”

Prediction of methyl orange dye (MO) adsorption using activated carbon with an artificial neural network optimization modeling

“…MO has been shown to be very hazardous, to damage the eyes, and could potentially result in long-term ocular harm [ 2 ]. Various techniques used for processes used in dye removal, These techniques include for example Ozonation [ 3 ], coagulation–flocculation [ 4 ], Photocatalytic oxidation [ 5 ] Algal treatment [ 6 ], Electrochemical oxidation [ 7 ], Membrane filtration [ 8 ], and adsorption [ [9] , [10] , [11] , [12] , [13] , [14] ]. Due to its adaptability, low cost, and simplicity of use, adsorption is regarded as the best wastewater treatment method.…”