The Recent Design of Ag3PO4-Based Photocatalyst for Renewable Energy and Environmental Applications

Introduction

The world is currently facing big challenges, especially in the fields of energy and the environment. The use of fossil fuels produces carbon dioxide gas, which influences global climate change. Fossil fuel combustion could have multiple threats to child health due to the emission of toxic particles and gases (Perera, 2017). The toxic air pollutant and climate change affected the developing fetus and young child. Therefore, a future energy source such as hydrogen is very important to replace fossil fuels. Environmentally friendly energy should be provided for our next generation.

To achieve such goals, the photocatalyst is one of the materials that can be chosen to solve energy and environmental problems. Photocatalysts can be applied for hydrogen production under solar irradiation (Wang et al., 2016), converting CO₂ to methanol (Wu et al., 2019), and converting biomass to electricity (W. Liu et al., 2014). These materials can also be applied for wastewater treatment (Arifan et al., 2018; Borges et al., 2016), organic pollutant degradation (Kusworo et al., 2021; Pasini et al., 2021), organic dye oxidation (Ariyanti et al., 2018; Wibowo & Sutanto, 2016), gas pollutant elimination (Sulaeman et al., 2010), and bacteria inactivation (N. Liu et al., 2021; Sutanto et al., 2015). The highest challenge of this material is to produce a highly active photocatalyst under solar light irradiation. With this approach, more sunlight energy could be harvested. The modification of iron-doped TiO₂ (Ebrahimi et al., 2021; Nasralla et al., 2018), nitrogen-doped TiO₂ (Asahi et al., 2001; Hidayanto et al., 2017; Pandiangan et al., 2018; Sutanto et al., 2017; S. Yin et al., 2003), and defect TiO₂ nanomaterials (Ariyanti et al., 2017), have been attempted to achieve this purpose. However, low activity has been found in these materials. Therefore, alternative photocatalysts such as Ag₃PO₄ should be explored. This chapter gives an overview of the latest developments of Ag₃PO₄-based photocatalysts for energy and environmental applications.

Ag₃PO₄-based materials are potential photocatalysts for energy and environmental applications. Ag₃PO₄-TiO₂ heterojunction (C. F. Liu & Perng, 2020), Z-scheme g-C₃N₄/Ag₃PO₄ nanocomposite (Raeisi-Kheirabadi & Nezamzadeh-Ejhieh, 2020), and Ag₃PO₄/MXene (Zhao et al., 2020), have been successful in initiating the water-splitting experiments. These Ag₃PO₄-based photocatalysts could be promising for producing hydrogen as renewable energy in the future. Besides the energy creations, the Ag₃PO₄-based photocatalysts could also be applied for organic pollutant degradation. Colour substances such as methylene blue, methyl orange, and rhodamine B could be easily oxidized by this modified photocatalyst (Yan et al., 2017). Other organic pollutants of phenol (Song et al., 2018), bisphenol (T. Li et al., 2019), and polyaromatic hydrocarbon (Yang et al., 2018) also could be degraded into carbon dioxide and water. For health and sanitary purposes, the Ag₃PO₄-based photocatalysts could potentially be applied as antibacterial agents (Seo et al., 2017). The modification of Ag₃PO₄ through Ag₃PO₄/α-Fe₂O₃ (Su et al., 2020), Fe₃O₄/SiO₂/ZnO/Ag₃PO₄ (Mao et al., 2020), and Bi₂MoO₆/Ag₃PO₄/Silk fibroin (Wang et al., 2021), led to excellent antibacterial photocatalysts.