2D Amorphous CoO Incorporated g‐C₃N₄ Nanotubes for Improved Photocatalytic Performance

Abstract

Hydrogen, as a clean fuel, has been considered as a promising alternative for traditional fossil fuels in the future. [1] The photocatalysis hydrogen evolution is identified as one of pollution-free methods to produce hydrogen on a large scale. [2][3][4] Since photo-induced water splitting on TiO 2 electrodes was discovered, great efforts have been made to develop catalysts for photocatalytic water splitting. [5,6] Up to date, various nanomaterials have been used as photocatalysts for the sunlightdriven H 2 evolution, including metal oxides/sulfide, carbonaceous materials. [7][8][9][10] Among them, CoO nanocrystal is a wellknown visible-light response (E g % 2.6 eV) photocatalyst that can be used for photocatalytic water splitting. [11] Unfortunately, the photocatalytic performance of CoO nanocrystals are far away from the satisfaction for practical large-scale applications. [12] In addition, the CoO photocatalystis can be easily deactivated after a short reaction. There are two main reasons have been reported, one of which corresponds to CoO nanoparticles aggregation after reaction, the other reason originates from the unintended thermo-induced oxidation of CoO during photocatalytic process, resulting in the poor stability. [13,14] Therefore, it is still challenging task to improve the activity and durability of CoO photocatalysts.Recently, several works have been reported that amorphous cobalt-based oxides play a critical role in improving the photocatalytic performance due to the high density of dangling bonds and active sites. [15][16][17] For example, the amorphous CoO (a-CoO) can be served as an efficient and long-term stability photocatalyst for water splitting. [18] Alternatively, the combination of a-CoO with other semiconductors to construct a 2D/2D heterojunction might be an available route to utilize the complementary advantages of each component and effectively separate the photogenerated electron-hole pairs, thus improving the photocatalytic activity. [19,20] Whereas, the preparation of CoO often requires the calcination of Co-containing reagents in an inert environment, and the obtained CoO is mostly a bulk material. [11,21] Undoubtedly, solving the CoO aggregation and synthesis 2D CoO nanosheets have been of significant importance for its practical application in photocatalysis. Therefore, it is still a big challenge about explore suitable strategies to achieve the preparation of 2D/2D CoO-based heterojunctions.Graphitic carbon nitride (g-C 3 N 4 ) is generally known as a typical metal-free layered polymer, which has attracted dramatic interest in the field of visible-light-induced

Generalized Multidentate Ligand Chelating‐Grafting Strategy for Construction of Amorphous Metal Oxides Based Triple‐Layered Nanotubes

“…To detect the active species, an appropriate amount of capture agents listed as isopropyl alcohol (IPA) capturing hydroxyl radicals (·OH), benzoquinone (BQ) capturing superoxide radical (), ethanol (EA) capturing VB‐holes, along with one control group without any scavengers, were carried out in the scavenger experiments of RhB degradation (Figure 7d). [ 43 ] As obviously seen, the decomposition of RhB is greatly hampered by the addition of BQ, indicating radicals play a major role in photocatalytic reaction. Whereas, the degradation efficiency is hardly affected after the addition of IPA, demonstrating that the ·OH is not the main active species.…”

Supercritical CO2‐Induced Amorphization in 2D Materials: Mechanism and Applications

“…With this method, they further fabricated the 2D amorphous CoO incorporated g-C 3 N 4 nanotubes for improved photocatalytic water splitting (Fig 26d). [75]…”

First principles of Fe/Co/Ni doping and the coexistence of O vacancy in the magnetic and optical properties of rutile TiO2(110) surface

“…The 2D/2D CN/a-ZnO heterojunction has abundant defects and Zn-N covalent bonding, large size, and perfect disordered interface, which can extend the light absorption range, increase the number of reaction sites, enhance the loading of the separation of the current, and promote charge transfer. Wang et al [15] investigated the incorporation of 2D amorphous CoO into g-C 3 N 4 nanotubes to improve the photocatalytic performance by CoO aggregation and thermally induced oxidation, and the results showed that the synthesized 2D/2D CN/a-CoO heterojunction significantly improved the degradation of rhodamine B, achieving an efficient space charge separation through Co-N bonds. Khatoon et al [16] studied the influence of Ni-doped ZnO on optical properties and magnetic properties by solvothermal synthesis method.…”