Photoluminescence amplification of cerium incorporated graphene oxide nanoparticles by photoinduced reduction: A mechanistic study highlighting structural orderness

Interaction of Aromatic Nitro Compounds and Fluoride Ions with Photoluminescent GO‐Ce Nanoparticles: Understanding the Role of Local Environment of Cerium

“…The characteristics emission peak of cerium (III) arises because of the transitions from the excited 5d orbital (D state) to 4 f orbital ( 2 F 5/2 and 2 F 7/2 states generated due to strong spin‐orbit coupling). The deconvoluted photoluminescence spectra shows four different emission bands due to the presence of differently located of the cerium ions (cerium ions present in two different locations of each luminescence band generating two new bands because of 5d→ 2 F 5/2 and 5d→ 2 F 7/2 transitions), cerium ions bound within the basal plane of GO moiety are facing relatively less polar environment and the cerium ions present in the outer surface of the GO moiety are facing highly polar environment [18] . Thermodynamic concept of photoinduced reduction in GO−Ce NPs is shown in SI Section 2.…”

“…Decrease in intensity of luminescence originating from disordered induced defect states suggest the decoupling of functional groups at the GO surface due to the binding between cerium ions and GO NPs, which leads to the activation of non-radiative channel to generate more trivalent Cerium via single electron transfer from antibonding orbitals of oxygenated functional groups to the vacant 4 f orbitals of tetravalent Ce. [18] Careful observation of the PL band reveals the presence of two types of cerium ions, one is within the basal planes and another is on the surface of the NPs. But further studies are required to establish the presence of two types of cerium in GO NPs.…”

“…ChemistrySelect moiety are facing relatively less polar environment and the cerium ions present in the outer surface of the GO moiety are facing highly polar environment. [18] Thermodynamic concept of photoinduced reduction in GOÀ Ce NPs is shown in SI Section 2.…”

“…Very recently Halder and co‐workers have incorporated cerium ions via non‐covalently bonded GO NPs, consisting of a large number of carboxylic functional groups and reported more than 100‐fold amplification of photoluminescence intensity compared to graphene oxide results from Photoinduced Reduction of non‐emissive Ce IV into luminescent Ce III accompanied via energy pumping of cerium by photoexcited GO NPs to the ordered GO−Ce nanoparticles. Decrease in intensity of luminescence originating from disordered induced defect states suggest the decoupling of functional groups at the GO surface due to the binding between cerium ions and GO NPs, which leads to the activation of non‐radiative channel to generate more trivalent Cerium via single electron transfer from antibonding orbitals of oxygenated functional groups to the vacant 4 f orbitals of tetravalent Ce [18] . Careful observation of the PL band reveals the presence of two types of cerium ions, one is within the basal planes and another is on the surface of the NPs.…”

Advanced Biological Applications of Cerium Oxide Nanozymes in Disease Related to Oxidative Damage

“…The lanthanide metal cerium has attracted a great deal of attention in a range of fields, including physics, chemistry, biology, and materials science. − Cerium ions form a fluorite crystal structure of cerium oxide with oxygen (O 2 ) atoms. Cerium oxide is widely used in industrial production as a component of polishing powder, glass decolorizing agents, high-temperature-resistant materials, catalytic materials, and solar cells − and is particularly important in catalysts. − Cerium atoms exhibit not only a fully reduced +3 valence state but also have a fully oxidized +4 valence state because Ce has two partially filled electron orbitals (4f and 5d) and many suborder excited states. − Cerium ions preferentially adopt the more stable Ce 4+ state in cerium oxide. Ce ions form crystals in a fluorite structure with eight O 2 atoms surrounding one cerium atom.…”