Recent Developments in Adsorption of Dyes Using Graphene Based Nanomaterials

Dyes are frequently let out into the environment along with wastewater sans necessary treatment. Fast, cost-effective, scientific and suitable elimination of dyes from wastewaters has been an important problem for researchers. Adsorption technique is a robust, well studied, widely employed and promising water treatment method. In the last decade, nanocarbon based adsorbents have gained attention in water treatment. These adsorbents are usually produced from low cost substrate and are found to be highly efficient than other adsorbents. Recently, graphene based nanomaterials are widely used as adsorbents to sorb various toxic organic contaminants from aqueous solutions. It showed high efficiency due to its chemical stability, structure, surface area and surface functional groups. So graphene are called as ‘miracle material’. Recently nanographene composites are proven to be a likely adsorbent for eliminating contaminants from the industrial effluents. In this chapter, we have presented briefly the synthesis of graphene and its other variants viz., GO, rGO and nano graphene composites. This chapter presents a small introduction to adsorption principles and adsorption isotherms. It explains the synthesis and use of nano graphene materials for the remediation of dyes. It also consolidates the recent literature available for dye adsorption using graphene materials and its mechanism

Photoelectrochemical Water‐Splitting Using CuO‐Based Electrodes for Hydrogen Production: A Review

The cost-effective, robust, and efficient electrocatalysts for photoelectrochemical (PEC) water-splitting has been extensively studied over the past decade to address a solution for the energy crisis. The interesting physicochemical properties of CuO have introduced this promising photocathodic material among the few photocatalysts with a narrow bandgap. This photocatalyst has a high activity for the PEC hydrogen evolution reaction (HER) under simulated sunlight irradiation. Here, the recent advancements of CuO-based photoelectrodes, including undoped CuO, doped CuO, and CuO composites, in the PEC water-splitting field, are comprehensively studied. Moreover, the synthesis methods, characterization, and fundamental factors of each classification are discussed in detail. Apart from the exclusive characteristics of CuO-based photoelectrodes, the PEC properties of CuO/2D materials, as groups of the growing nanocomposites in photocurrent-generating devices, are discussed in separate sections. Regarding the particular attention paid to the CuO heterostructure photocathodes, the PEC water splitting application is reviewed and the properties of each group such as electronic structures, defects, bandgap, and hierarchical structures are critically assessed