Essential roles of defects in pure graphene/Cu2O photocatalyst

Inquiring the photocatalytic activity of cuprous oxide nanoparticles synthesized by a green route on methylene blue dye

“…From an extensive literature study, we concluded that a chemical method such as adsorption process is an economical and efficient route for elimination of toxic dyes from polluted water [9][10][11][12]. In this regards, various low-cost adsorbents such as fly ash, metal sulfides (Ag 2 S), and metal oxides (titania TiO 2 , cuprous oxide Cu 2 O) have already been tested to treat polluted water [4,[9][10][11][12][13]. In recent years, semiconductor nanoparticles (NPs) were extensively used by scientists and academicians around the globe for the removal of various organic dyes via adsorption route.…”

“…Among the various semiconductor metal oxides as photocatalyst, Cu 2 O NPs find a special place in photocatalysis under visible light [10][11][12][14][15][16]. Wide applications of this oxide NPs are mainly owing to its nontoxicity, easy availability of cheap and up-scalable synthetic routes, lying of the band gap (i.e., 2.17 eV) in the visible range, tunability of band gap, and strong tendency to adsorb molecular oxygen which helps in scavenging the photogenerated electrons so that electron-hole pairs recombination can be restrained easily at the interface [10][11][12][14][15][16].…”

“…Wide applications of this oxide NPs are mainly owing to its nontoxicity, easy availability of cheap and up-scalable synthetic routes, lying of the band gap (i.e., 2.17 eV) in the visible range, tunability of band gap, and strong tendency to adsorb molecular oxygen which helps in scavenging the photogenerated electrons so that electron-hole pairs recombination can be restrained easily at the interface [10][11][12][14][15][16]. It is reported that size and shape are of paramount importance in tailoring the various properties and applications of the Cu 2 O NPs.…”

“…A variety of Cu 2 O nanostructures such as wires, boxes, cubes, truncated cubes, octahedra, nanocages, nanomultipods, spheres, and a variety of hollow structures have already been synthesized and tested for their photocatalytic activity on various organic compounds [14,15]. To develop diverse architectures of Cu 2 O, the various methods widely used includes hydrothermal method, microemulsion method, surfactantassisted route, and wet chemical method [10][11][12][14][15][16]. Sun et al [9] have reported an enhanced photocatalytic activity for Cu 2 O-graphene oxide (GO) nanocomposite synthesized via solvothermal route towards Rhodamine B (RhB) dye.…”

“…But, nearly 70 % methyl orange (MO) degradation was reported for this nanocomposite after a long irradiation time of 300 min. In another article, Zhang et al [11] A few reports are available on photocatalytic activity study of Cu 2 O NPs synthesized by green chemical route. Cu 2 O microcrystals with well-formed facets were synthesized by a simple hydrothermal method by Zheng et al [14] and investigated the surface stabilities and photocatalytic properties of the synthesized Cu 2 O microcrystals.…”