An Overview of the Photocatalytic H2 Evolution by Semiconductor-Based Materials for Nonspecialists

Abstract

The solar-to-chemical energy conversion is promising to tackle sustainability challenges toward a global future. The production of H 2 from sunlight represents an attractive alternative to the use of carboniferous fossil fuels to meet our energy demands. In this context, the water splitting reaction photocatalyzed by semiconductors that can be excited under visible or near-infrared light excitation represents an attractive route to the clean generation of H 2. In this review, we present an overview of the most important concepts behind the H 2 generation, from water splitting, promoted by semiconductor-based systems for readers that were recently introduced to the water splitting topic. Then, we present the main classes of photocatalysts based on semiconductors. For each class of semiconductors, we focused on the examples that lead to the highest activities towards the H 2 production and discuss the operation principles, advantages, performances, limitations, and challenges. We cover metal oxides, sulfides, and nitrides. We also discuss strategies in which these materials are combined, including hybridization with metal nanoparticles, other semiconductors, and carbon dots, to achieve improved performances and circumvent the limitations of the individual counterparts.

Hydrothermal Synthesis of Silver Decorated Reduced Graphene Oxide (rGO) Nanoflakes with Effective Photocatalytic Activity for Wastewater Treatment

“…This phenomenon can greatly enhance the charge separation efficiency, once it can induce the directional migration of photogenerated electrons from the semiconductor to the metal. In other words, it can lead to the generation of effective electron trapping site to suppress the electron-hole recombination [48].…”

Hydrothermal Synthesis of Silver Decorated Reduced Graphene Oxide (rGO) Nanoflakes with effective Photocatalytic Activity for Wastewater Treatment

“…This phenomenon can greatly enhance the charge separation efficiency, once it can induce the directional migration of photogenerated electrons from the semiconductor to the metal. In other words, it can lead to the generation of effective electron trapping site to suppress the electron-hole recombination [49].…”

Photocatalytic degradation of ibuprofen using titanium oxide: insights into the mechanism and preferential attack of radicals

“…The presence of the OHc radical was confirmed through a model reaction using salicylic acid as a probe molecule.À c) and hydroperoxide (HO 2 c) radicals to degrade the organic materials and mineralize the contaminant to carbon dioxide and water. [11][12][13][14] Heterogeneous photocatalysis…”

“…À c) and hydroperoxide (HO 2 c) radicals to degrade the organic materials and mineralize the contaminant to carbon dioxide and water. [11][12][13][14] Heterogeneous photocatalysis…”