Self-Assembled Supramolecular Hybrid of Carbon Nanodots and Polyoxometalates for Visible-Light-Driven Water Oxidation

Abstract

Water splitting is considered the most attractive pursuit in the field of solar energy conversion. In this study, we report the synthesis and application of a supramolecular hybrid of carbon nanodot (CD) and cobalt polyoxometalate (Co-POM) to solar water oxidation. The self-assembly of the alginate-based CD and Co-POM led to the formation of a spherical hybrid of CD/Co-POM. Owing to the facile transfer of photogenerated holes from CD under visible light irradiation, the hybrid donor-acceptor type of CD/Co-POM enabled the rapid scavenging of holes and accumulation of a long-lived oxidation state of Co-POM for efficient solar water oxidation, outperforming conventional [Ru(bpy)]-based systems. We believe that this study offers new insights into the development of CD-based nanocomposites with various photocatalytic and optoelectronic applications.

Structural and Optical Characteristics of PVA:C-Dot Composites: Tuning the Absorption of Ultra Violet (UV) Region

“…Because of the abundance of oxygen/hydrogen-containing species such as –OH and –COOH on the surfaces of CNDs, they are chosen as fillers to enhance the hydrogen bonding [4]. Lately, carbon nano-dots (CNDs) have emerged as a new family of light-harvesting materials with remarkable advantages including strong and broad optical absorption, high chemical stability, excellent electron- and hole-transfer capability, and low toxicity [5]. The incorporation of CDs within polymer matrices is under intense study and thus can be utilized in many photonic and optoelectronic applications and integrated in real devices [6].…”

Zwitterionic Conjugated Surfactant Functionalization of Graphene with pH‐Independent Dispersibility: An Efficient Electron Mediator for the Oxygen Evolution Reaction in Acidic Media

“…Both the EIS and ECSA analysis suggest a synergistic effect of PDI-NO@G and RuPOM for the OER. According to previous reports, highly negatively charged polyoxometalates can strongly interact with positively charged species; [36,37] thus, it can be expected that PDI-NO@G with positively charged tertiary amine (N + ) groups can strongly interact with RuPOM, facilitating electron transfer between the two. Combined with the EIS analysis, these results support the hypothesis that PDI-NO@G can function as an efficient electron mediator and increase the overall OER reaction (Figure 5e).…”

Polyoxometalates: Tailoring metal oxides in molecular dimension toward energy applications

“…351,352 Cobaltbased polyoxometalates have been applied to energy systems such as the redox couple in dye-sensitized solar cells. 43,349,[353][354][355][356][357][358][359] A number of other transition metalbased polyoxometalates have been investigated, such as silver-containing polyoxometalates, 226,[360][361][362][363][364][365] zinccontaining polyoxometalates. 366 polyoxotantalate, [367][368][369][370][371][372][373][374][375][376][377][378][379][380][381][382][383][384] ruthenium-containing polyoxometalates, [385][386][387] coppercontaining polyoxometalates, [388][389][390] chromium-containing polyoxometalates, 391 and polyoxoaurates [392][393]…”

“…“Polyoxoiron” is rarely obtained, but the iron element is frequently introduced into polyoxometalates for various energy applications; for example, it has been employed to enhance the ZnO‐based solar cell performance via the construction of a metal‐organic framework owing to the excellent electron‐separation properties . Cobalt‐based polyoxometalates have been applied to energy systems such as the redox couple in dye‐sensitized solar cells . A number of other transition metal‐based polyoxometalates have been investigated, such as silver‐containing polyoxometalates, zinc‐containing polyoxometalates .…”