Smallest [5,6]fullerene as building blocks for 2D networks with superior stability and enhanced photocatalytic performance

Abstract

The assembly of molecules to form covalent networks can create varied lattice structures with distinct physical and chemical properties from conventional atomic lattices. Using the smallest stable [5,6]fullerene units as building blocks, various 2D C${}_{24}$ networks can be formed with superior stability and strength compared to the recently synthesised monolayer polymeric C${}_{60}$. Monolayer C${}_{24}$ harnesses the properties of both carbon crystals and fullerene molecules, such as stable chemical bonds, suitable band gaps and large surface area, facilitating photocatalytic water splitting. The electronic band gaps of C${}_{24}$ are comparable to TiO${}_2$, providing appropriate band edges with sufficient external potential for overall water splitting over the acidic and neutral pH range. Upon photoexcitation, strong solar absorption enabled by strongly bound bright excitons can generate carriers effectively, while the type-II band alignment between C${}_{24}$ and other 2D monolayers can separate electrons and holes in individual layers simultaneously. Additionally, the number of surface active sites of C${}_{24}$ monolayers are three times more than that of their C${}_{60}$ counterparts in a much wider pH range, providing spontaneous reaction pathways for hydrogen evolution reaction. Our work provides insights into materials design using tunable building blocks of fullerene units with tailored functions for energy generation, conversion and storage.

15 pages, 8 figures, 2 tables

References in corpus (6)

• Restoring the density-gradient expansion for exchange in solids and surfaces
• Generalized gradient approximation for solids and their surfaces
• Monolayer fullerene networks as photocatalysts for overall water splitting
• Stability and strength of monolayer polymeric C${}_{60}$
• Boosting photocatalytic water splitting of polymeric C${}_{60}$ by reduced dimensionality from 2D monolayer to 1D chain
• A Small Fullerene (C24) may be the Carrier of the 11.2 micron Unidentified Infrared Band

Cited by in corpus (5)

• Tuning electronic and optical properties of 2D polymeric C${}_{60}$ by stacking two layers
• Monolayer C${}_{60}$ networks: A first-principles perspective
• Electronic structure of fullerene nanoribbons
• C${}_{60}$ building blocks with tuneable structures for tailored functionalities
• Anisotropic and isotropic elasticity and thermal transport in monolayer C${}_{24}$ networks from machine-learning molecular dynamics