Natural Volcanic Material as a Sustainable Photocatalytic Material for Pollutant Degradation under Solar Irradiation

Abstract

Recently, photocatalysis has been demonstrated as a solid approach for efficient wastewater cleaning. Using natural materials as photocatalysts means a promising solution to develop green catalysts for environmental purposes. This work aimed to study the suitability of a natural volcanic material (La Gomera, Canary Islands, Spain) as a photocatalytic material for the degradation of pollutants in wastewater with solar energy. After analysing the properties of the natural material (BET surface 0.188 m2/g and band-gap of 3 eV), the photocatalytic activity was evaluated at laboratory and pilot plant scale for the degradation of methylene blue (MB) in water (50 mg L−1), at 20 °C, during a period of 4 h, under UV/Vis light and solar irradiation. Photolytic and adsorption studies were developed to distinguish the photocatalytic contribution to the wastewater decontamination process by photocatalysis. Our results enable us to determine the viability of black sand as a photocatalytic material activated by solar irradiation (photodegradation of MB up to 100% by using solar energy), developing a natural and green photocatalytic system with significantly high potential for application in a sustainable wastewater cleaning process.

Constructing Heterogeneous Photocatalysts Based on Carbon Nitride Nanosheets and Graphene Quantum Dots for Highly Efficient Photocatalytic Hydrogen Generation

“…Since the TiO 2 discovery as a photocatalyst for water splitting, different semiconductor materials with specific energy-band positions have been employed as photocatalytic materials for pollutant degradation, H 2 production from water splitting, and carbon dioxide reduction [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 ]. Photocatalysts are considered to be an efficient technique to generate hydrogen energy, while also addressing environmental and energy issues.…”

An Exploration of the Four‐Decade‐Long History of Photocatalytic Water Treatment: Analysis of Key Advancements, Underlying Relationships, and Failures along the Way

“…Before 2010, based on the author's total link strength, Guillard (43,2001), Inoue (53,2002), Yamashita (50,2006), and Domen (76,2006) had the most coauthorship links among the authors. Between 2010 and 2015, Dionysiou (73,2011), Mantzavinos (36,2012), and Li (58,2014) had the highest coauthorship links among authors. The citation trend (Figure 3b) follows the tendency described in Figure 3a; however, incorporating total link strength into bibliometric analysis enhances our understanding of an author's impact, collaboration, and influence within their field.…”

“…3) It is ecofriendly, with no greenhouse gas emissions. [58] Titanium dioxide, the most widely used photocatalyst for water treatment, is a wide-bandgap semiconductor photocatalyst that can be excited to generate electron-hole pairs after exposure to light. [59] However, titanium dioxide can only be excited by UV light (shorter than 387.5 nm), which utilizes only a small part of the solar spectrum (%3% on Earth and %10% in outer space).…”

Tuning of surface oxygen vacancies for enhancing photocatalytic performance under visible light irradiation in Sb2WO6 nanostructures

“…According to the World Health Organization (WHO), more than 2000 million people all over the world are using polluted water every day for various activities. 2 Therefore, the study of emerging water pollutants such as dyes and pharmaceutical compounds has become an important research area. These compounds remain in waste-water and water bodies as micro-pollutants for a long time and pose a threat to marine life.…”