Boosting the Optical Absorption of Melanin-like Polymers

Abstract

As a typical type of melanin-inspired materials, polydopamine (PDA) has been widely used in photothermal conversion and energy harvesting applications due to its broad spectral absorption feature, but its limited absorption in the visible light region severely hinders further utilization. Although enhancing the visible light absorption and photothermal performance of PDA is urgent, it is quite difficult to achieve this goal via structural tailoring strategies because of the complicated and disordered structure within PDA. To address this issue, we reported a facile approach involving nitrogen-containing heterocycles toward the design of two new kinds of PDA nanomaterials. The introduction of nitrogen-containing heterocycles greatly reduced the lowest unoccupied molecular orbital of the molecular segments and then promoted electron delocalization in the local area. We verified the changes of energy bandgap and exciton decay of nitrogen-containing heterocycle-doped PDA through spectral analysis, density functional theory calculation, and electrostatic potential distribution on the molecular surface. Therefore, these heterocycle-doped PDAs exhibited improved visible light absorption and photothermal performances, which can be used in solar power generation applications. This work provides new opportunities for the rational design and structural tailoring of bioinspired photothermal materials.

A melanin-inspired robust aerogel for multifunctional water remediation

“…Melanin is a family of biopolymers widely distributed in natural organisms (e.g., animals, plants, bacteria, and fungi) and possesses many intriguing physicochemical functions, including radiation protection, thermal regulation, pigmentation, metal ion-chelation capacity, and free-radical scavenging property. 13,[18][19][20][21][22][23][24][25] Specifically, its excellent light harvesting ability demonstrates promising potential in photothermal conversion applications. 6,15,[26][27][28][29] Moreover, benefiting from the presence of abundant functional groups (e.g., catechol, amine, and imine) within the structure, melanin can not only interact with a variety of metal ions via catecholate-metal ion coordination interactions, but also impart strong affinity with many types of organic molecules through various types of noncovalent interactions (e.g., p-p interactions, hydrogen bonding, cation-p interactions, and complexation).…”

“…, animals, plants, bacteria, and fungi) and possesses many intriguing physicochemical functions, including radiation protection, thermal regulation, pigmentation, metal ion-chelation capacity, and free-radical scavenging property. 13,18–25 Specifically, its excellent light harvesting ability demonstrates promising potential in photothermal conversion applications. 6,15,26–29 Moreover, benefiting from the presence of abundant functional groups ( e.g.…”

A bioinspired antibacterial and photothermal membrane for stable and durable clean water remediation

“…Note that the formation of the donor-acceptor (D-A) domain within the samples by various oligomer conjugates could decrease the energy bandgaps of the PDA-based NPs and promote the electron delocalization, resulting in the enhancement of light absorption of the NPs for more energy intake. [44][45][46] In order to verify these points in this system, a theoretical simulation of potential molecular bound structures within PDA/TOB NPs was first carried out by using the density functional theory (DFT) technique at the B3LYP/6-31G(d, p) level. As shown in Fig.…”

Robust and multifunctional natural polyphenolic composites for water remediation

“…Taking the most typical bioinspired synthetic polydopamine (PDA) as an example, our group previously developed a series of strategies to regulate its light-harvesting ability, thus further enhancing its photothermal conversion and solar distillation efficiency. [54][55][56][57][58][59][60][61][62][63][64] Nevertheless, the practical large-scale application of PDA may be limited because of its high cost. Therefore, the natural polyphenols have attracted increasing interests owing to their ubiquitous presence in plants and retaining many advantages of PDA.…”