Metallic Pt and PtO₂ Dual-Cocatalyst-Loaded Binary Composite RGO-CN_x for the Photocatalytic Production of Hydrogen and Hydrogen Peroxide

Abstract

Photocatalytic overall water splitting is considered as an ideal solution to the energy crisis by converting inexhaustible solar energy into hydrogen energy. However, the practical application of photocatalytic overall water splitting is hindered by the challenges including unfavorable four-electron/hole kinetics and H 2 /O 2 separation. Here, the binary composite of reduced graphene oxide and graphitic carbon nitride decorated by the double cocatalyst (Pt and PtO 2 ) is reported to achieve excellent photocatalytic water reforming performance for H 2 and H 2 O 2 production via the two-electron pathway. In addition, a unique structure with Pt and PtO 2 as active sites for reduction and oxidation, respectively, is further proposed. This unique structure promotes the separation of photogenerated carriers and holes, extends the light absorption, and thus significantly improves photocatalytic activity with the highest H 2 evolution rate of 5.7 μmol•h −1 . What's more, the addition of reduced graphene oxide can improve the photocatalytic stability of the catalyst by reinforcing the chemical connection between graphitic carbon nitride and PtO x (Pt, PtO 2 ). This work highlights the important role of using graphitic carbon nitride for heterogeneous catalysis and reveals the possibility of designing multiple components to realize an efficient photocatalytic water reforming.

Site‐Specific Electron‐Driving Observations of CO2‐to‐CH4 Photoreduction on Co‐Doped CeO2/Crystalline Carbon Nitride S‐Scheme Heterojunctions

“…[11,12] This polymeric carbon nitride (PCN) has ligand flexibility with regular atomic coordination, [13,14] especially for a highly crystalline one, which enables molecular-level investigations on dynamic charge transfer across the interfacial configuration. [15,16] Particularly, direct integration of PCN with metal oxide in heterogeneous photocatalysis, including transition metal oxide (e.g., Co 3 O 4 , [17] ZnO, [18] and CuO [19] ), noble metal oxide (e.g., PdO, [20] RuO 2 , [21] and PtO 2 [22] ), and rare earth oxide (e.g., CeO 2 [23] and La 2 O 3 [24] ), calls for useful strategy to facilitate the interfacial electron modulation. Despite substantial efforts on developing PCN-based heterogeneous composite for high CO 2 RR, [25,26] the efficiency of photoinduced kinetic coupling, namely, charge transfer, is inherently short-term durability, which hampers the multiple electrons-involving reduction for terminal CH 4 generation.…”

Carbon nitride based Schottky junction with a Ni–Mo synergistic interaction for highly efficient photocatalytic hydrogen production

“…The Schottky barrier formed would prevent the reverse transfer of photogenerated electrons from NiMoP 2 to CN, improving the carrier separation efficiency. 21,50…”

Synergistic photo-enhanced electrocatalysis of Pt–ZnO–Bi2O3 heterojunction for methanol oxidation under visible light illumination

“…70,71 The ZnO (272 nm) and Bi2O3 (254 nm) and a tail absorption was noticed in the visible region because of the Pt deposition in Bi2O3 and all ZnO-Bi2O3 catalysts. 59,[72][73][74] The inclusion of Pt to ZnO also induces light absorption towards the vis zone. 75,76 This might be due to the presence of a small amount of impurity in metallic Pt ie, PtO or Pt(OH)2, and PtO2 on the surface of ZnO-Bi2O3.…”