Enhanced Photocatalytic H₂-Production Activity of g-C₃N₄ Nanosheets via Optimal Photodeposition of Pt as Cocatalyst

Abstract

Photocatalytic H2 production plays an important role in alleviating fossil fuel crisis and constructing a sustainable world. Graphitic carbon nitride nanosheets (CNS), coupled with cocatalyst platinum (Pt) and hole sacrificial agent triethanolamine (TEOA), often show excellent H2-production activity. However, the question on maximizing Pt amount in this given TEOA-contained system still remains unsolved. Herein, it was found that the order of adding TEOA into the reaction system before or after the photodeposition of Pt had a significant effect on photocatalytic hydrogen production over CNS. Specifically, the content of Pt was lower when TEOA was added beforehand, implying that a strong interaction existed between the Pt-precursor H2PtCl6 and TEOA, thus curbing the photoreduction to metallic Pt. Therefore, a roughly 4-fold increment in hydrogen production activity (4210.8 vs. 972.2 μmol h–1 g–1) was obtained by merely swapping the sequence of the addition of TEOA. Moreover, the apparent quantum efficiency (AQE) at 420 nm wavelength was also quadrupled from 0.63% to 2.4%. Simultaneously, the mechanism behind this phenomenon was thoroughly investigated. This work highlights the importance of experimental design and provides a facile approach in fully utilizing noble metallic Pt.

Conjugated Electron Donor–Acceptor Hybrid Polymeric Carbon Nitride as a Photocatalyst for CO2 Reduction

“…The peaks located in the range between 2900 to 3300 cm −1 are broad peaks ascribed to the adsorbed H 2 O molecules and N-H vibrations originated from the partial condensation [41]. The peaks in the range between 1100–1800 cm −1 correspond to the typical stretching vibration modes of C-N and C=N heterocycles [42,43]. The peak appearing at 810 cm −1 originates from the significant bending vibration of the s-triazine motifs [44].…”

Triethanolamine-mediated photodeposition formation of amorphous Ni-P alloy for improved H2-evolution activity of g-C3N4

“…As a consequence, H 2 -evolution cocatalysts have been demonstrated to be an ideal strategy to promote the photoexcited electron-hole pair separation, reduce the overpotentials for H 2 evolution, and subsequently enhance the interfacial catalytic efficiency of the photocatalysts [17][18][19]. It is well known that the noble metals (Au [20], Pt [21,22], Pd [23], etc.) are regarded as mosteffective cocatalysts for photocatalytic H 2 evolution.…”

In situ synthesis of metal‐free N‐GQD@g‐C 3 N 4 photocatalyst for enhancing photocatalytic activity

“…However, single g-C 3 N 4 exhibited low photocatalytic activity due to low separation efficiency of electron-hole, restricting its real applications [6]. Recently, co-catalysts were used to tune band structures, improving separation efficiency of electron-hole [7][8][9][10][11][12][13][14][15], such as noble metal (e.g. Au, Ag and Pt), inorganic semiconductor (e.g.…”