Supramolecular organic nanofibers with highly efficient and stable visible light photooxidation performance

Abstract

The development of organic materials for visible light driven photocatalytic is regarded as one of the most promising avenues to solve environment and solar-energy utilization issue. Here, we present that one-dimensional supramolecular organic nanofibers, self-assembled by a carboxy-substituent perylene diimide (PDI) molecule through H-type π-π stacking and hydrogen bonding, can act as a robust and effective photocatalyst for both organic pollutants degradation and water oxidation under visible light without the apparent need for an added metal co-catalysts. We corroborate that the highly efficient and stable activity of such supramolecar photocatalyst are attributed to the introduction of terminal carboxyl group, which leads to well-defined and stable Htype π-π stacking, and constructs the internal electric field in supramolecular nanofibers, thereby resulting in the deepening of valence band (VB) and the enhancement of migration and separation efficiency of photo-induced charge carriers. Our findings may help the development of semiconducting-based organic supramolecular materials for applications in environment protection and water splitting.

Fabrication of vertical orthorhombic/hexagonal tungsten oxide phase junction with high photocatalytic performance

“…[44] The photoelectrochemical performances of the samples were studied using photocurrent-time curves and the electrochemical impedance spectra (EIS). In order to further study the photodegradation mechanism, the trapping experiments using t-BuOH (•OH scavenger), [44] EDTA-2Na (hole scavenger) [44] and p-benzoquinone (•O 2 -scavenger) [46]were carried out, as shown in Fig. 12a MO over the same sample decreases obviously after adding p-benzoquinone (Fig.12b).…”

“…However, some researchers also reported the generation of •O 2 -by the photocatalysts with similar conduction band edge, and in some cases, •O 2 -can be the main reactive species. [46,47] Since the band gap of WO 3 is about 2.8 eV, under  443nm light irradiation, some electrons can be excited to be more negative potentials than the CBM to react with oxygen to generate superoxide radicals. [47].…”

Excited State Dynamics of Perylenediimide films with Isopropyl phenyl- and Undecane-Substitution

“…Recently, studies on PDIs have been revived concerning their potential applications in field effect transistor [1][2] , photovoltaic [3][4] , light emitting diodes 5 , degradation of organic compounds and photocatalytic anticancer treatment. [6][7][8][9][10] The flat molecular structure in PDI that facilitates intermolecular interactions with neighboring molecules, as a result, supermolecules can be formed by molecularly stacking with side-by-side and/or head-to-tail in the solid. 11 In these supermolecules, the stacking modes have great impact on their optical properties, catalytic performance, solubility, and so on.…”

Enhancement of the degradation ability for organic pollutants via the synergistic effect of photoelectrocatalysis on a self-assembled perylene diimide (SA-PDI) thin film

“…Especially, a perylene diimide (PDI) supramolecular organic photocatalyst that acted as a special n-type nanomaterial was formed through the self-assembly of PDI molecules. Due to the high charge carrier mobility and electron affinity, it could be widely used in the degradation of organic pollutants under visible light irradiation [31][32][33][34][35]. Some significant methods such as copolymerization [36], doping [37], supermolecular assembly [33], and surface heterojunction design [38][39][40] have been reported for increasing the catalytic activity.…”