Edge‐Functionalized Graphene Nanoplatelets as Metal‐Free Electrocatalysts for Dye‐Sensitized Solar Cells

Abstract

A scalable and low‐cost production of graphene nanoplatelets (GnPs) is one of the most important challenges for their commercialization. A simple mechanochemical reaction has been developed and applied to prepare various edge‐functionalized GnPs (EFGnPs). EFGnPs can be produced in a simple and ecofriendly manner by ball milling of graphite with target substances (X = nonmetals, halogens, semimetals, or metalloids). The unique feature of this method is its use of kinetic energy, which can generate active carbon species by unzipping of graphitic CC bonds in dry conditions (no solvent). The active carbon species efficiently pick up X substance(s), leading to the formation of graphitic CX bonds along the broken edges and the delamination of graphitic layers into EFGnPs. Unlike graphene oxide (GO) and reduced GO (rGO), the preparation of EFGnPs does not involve toxic chemicals, such as corrosive acids and toxic reducing agents. Furthermore, the prepared EFGnPs preserve high crystallinity in the basal area due to their edge‐selective functionalization. Considering the available edge X groups that can be selectively employed, the potential applications of EFGnPs are unlimited. In this context, the synthesis, characterizations, and applications of EFGnPs, specifically, as metal‐free carbon‐based electrocatalysts for dye‐sensitized solar cells (DSSCs) in both cobalt and iodine electrolytes are reviewed.

Sb2S3 Thickness-Related Photocurrent and Optoelectronic Processes in TiO2/Sb2S3/P3HT Planar Hybrid Solar Cells

“…In Sb 2 S 3 -based photovoltaic device, photoelectric conversion efficiency (PCE) has reached to 5.7–7.5% by improved technology and device design [1, 2, 7–10]. However, current efficiencies of solid-state devices still remain low compared to other photovoltaic devices, such as dye-sensitized solar cells [11] and perovskite solar cells [12]. At present, most of the works usually focus on finding the best technology to get better optoelectronic performance in solid-state devices [7–10, 13–15].…”

Activated Graphene Nanoplatelets Decorated with Carbon Nitrides for Efficient Electrocatalytic Oxygen Reduction Reaction

“…[14] By incorporating these CN nanostructures in GNPs, not only the large amount of N but also the large number of pyridinic N could be introduced and could significantly reduce the work function. [7c,14] It is also possible that by introducing nanoporosity in these CN/GNPs nanostructures, [15] the number of active sites could be increased. Hence, in this article, we report a unique method of introducing both nanoporosity and electrochemically active CN matrix in the GNPs through a simple integration of chemical activation and CN precursor polymerization.…”

Identify the impact of the covalent-bonded carbon matrix to FeN4 sites for acidic oxygen reduction

“…The tailorability of building blocks as well as inherent durability indwelling in covalent bonds endows them with excellent electrocatalytic characters. [36][37][38][39][40][41][42][43][44] Here, we report a proof-ofconcept study on the evaluation of carbon environment covalent-connected to FeN 4 sites on their catalytic activity via this pyrolysis-free approach. Speci cally, we designed a series of fully π-conjugated COPs, which contained well-de ned FeN 4 con gurations whereas discrepant delocalized conjugated carbon matrix connected to FeN 4 sites.…”