Chapter 1 -- Introduction to green nanostructured photocatalysts

Abstract

Recently, because of major concerns regarding fossil fuels, research in modern societies has focused on the utilization of alternative renewable energy sources in order to meet future energy demands. Solar energy is recognized as the primary source of renewable energy due to its year-round availability and its applications in various fields, such as heating, water splitting, and electricity generation using photocatalysts. The major drawbacks of solar energy conversion systems are their lower conversion efficiency, higher manufacturing and replacement costs, and health and environmental impacts of the materials employed. In order to eliminate such obstacles, many studies have focused on the energy and cost efficiency of solar cells (particularly dye-sensitized solar cells and thin-film solar cells), water-splitting devices, and CO2-capturing systems using various photocatalytic green nanomaterials, such as binary and ternary metal oxides, microorganisms (bacteria, algae, and viruses), and other catalysts and cocatalysts. These materials have been extensively studied because of their many advantages: chemical stability, tunable band gap structures, and abundance on Earth. In this book, we discuss the fundamentals of solar energy conversion, green synthesis approaches using these photocatalysts, the natural photosynthetic system, water splitting, CO2 capture, and organic and inorganic contaminant removal processes using photo-active green nanomaterials, as well as the theory behind these processes and standard measurements for comparisons. We also provide an update of recent developments in the field for the benefit of readers.