Dual Cocatalysts Synergistically Promote Perylene Diimide Polymer Charge Transfer for Enhanced Photocatalytic Water Oxidation

Abstract

Water oxidation is a critical reaction in artificial photosynthesis which is limited by a high reaction energy barrier and often requires matching cocatalysts. Dual cocatalysts Co3O4 and Pt are combined with a perylene diimide (PDI) polymer, accomplishing a photocatalytic O2 production rate of 24.4 mmol g–1 h–1 under visible light irradiation, which is a 5.4-fold enhancement compared with PDI alone. Moreover, the apparent quantum yield of the O2 evolution reaction reaches 6.9% at 420 nm and remains 1.2% at 590 nm. The dual cocatalysts-constructed interfacial electric fields provide an anisotropic driving force for photogenerated holes to Co3O4 and electrons to Pt, synergistically improving the spatial charge separation efficiency for water oxidation. Co3O4 molecules serve as active sites for the water oxidation reaction to improve the utilization of photogenerated holes on the surface. This work provides a valuable demonstration of the interaction process and mechanism of cocatalysts, guiding the selection of cocatalysts for high-efficiency solar energy conversion.

Schottky Junction Enhanced Photosynthesis of Hydrogen Peroxide by Ultrathin Porous Carbon Nitride Supported Ni Nanoparticles

“…Based on the CPD mapping image (Figure h), the average CPDs for UPGCN and Ni were calculated to be −7 mV and +11 mV, respectively, with the reference CPD of highly oriented pyrolytic graphite (HOPG) established at 0 mV. Following this, the work functions were ordered as Φ Ni > Φ UPGCN , in accordance with the equation CPD = (Φ s – Φ p )/ e , where Φ p denotes the work function of the probe and Φ s that of the samples . Driven by different work functions, electrons move from the conduction band of UPGCN to Ni NPs, forming a Schottky barrier.…”

“…Following this, the work functions were ordered as Φ Ni > Φ UPGCN , in accordance with the equation CPD = (Φ s − Φ p )/e, where Φ p denotes the work function of the probe and Φ s that of the samples. 54 Driven by different work functions, electrons move from the conduction band of UPGCN to Ni NPs, forming a Schottky barrier. Under visible light excitation, UPGCN injects more electrons into Ni NPs to obtain enhanced charge separation.…”

Cocatalyst-modified In2S3 photocatalysts for C–N coupling of amines integrated with H2 evolution

“…As the electrons are withdrawn, the energy band of In 2 S 3 bends upwards, which leads to an accumulation of positive charges on In 2 S 3 with the negative charges on PdS, resulting in the formation of the interfacial electric field (IEF) directing from In 2 S 3 to PdS. 53 When illuminated by visible light, the relocation of photoexcited holes remaining on the valence band (VB) of In 2 S 3 to PdS is accelerated by the forceful driving force served by the IEF, while the photogenerated electrons on the conduction band (CB) of In 2 S 3 are blocked back to In 2 S 3 by IEF and the upward energy band bending (Fig. 4h).…”

Synergistic Defect Sites and CoOx Nanoclusters in Polymeric Carbon Nitride for Enhanced Photocatalytic H2O2 Production

“…As shown in Figure d, the Co 2p spectra exhibited two peaks located at 781.6 and 796.3 eV, which were assigned to the 2p 3/2 orbital and 2p 1/2 orbital of Co, respectively. With further deconvolution, the characteristic peaks corresponding to the oxidation state of Co (II) at 782.2 and 797.9 eV and Co (III) at 780.9 and 796.7 eV were obtained . In addition, the satellite peaks centered at 787.2 and 802.9 eV were identified as the fingerprint peaks of the Co (II) oxidation state.…”