Growth of ZnO Nanorods on Graphitic Carbon Nitride gCN Sheets for the Preparation of Photocatalysts with High Visible‐Light Activity

Abstract

The light photoresponse, the separation of photogenerated charge carriers and the specific surface area are of great importance for the development of semiconductor-based photocatalysts. We report the anchorage of small-sized ZnO nanorods with a length of ca. 38 nm at the surface of graphitic carbon nitride (gCN) sheets. The gCN loading in the ZnO/gCN composites was varied and the materials characterized by TEM, XRD, XPS, BET and UV-vis diffuse reflectance spectroscopy. The ZnO/gCN (10 %) composite exhibits a high photocatalytic activity for the degradation of dyes (Orange II, Resazurin and Reactive Black 5) under visible light irradiation of low intensity (2.5 mW/cm 2 ) and for salicylic acid under simulated sunlight irradiation (5 mW/cm 2 ). These results are supported by photoluminescence, photocurrent and electrochemical impedance spectroscopy measurements. The photocatalytic activity originates from synergistic effects in ZnO/gCN composites including a high specific surface area (60.4 m 2 /g), an enhanced visible light absorption capacity and the charge carriers separation. The ZnO/gCN photocatalyst exhibits a high stability and could be reused up to ten times with no loss of efficiency. A mechanism is proposed for the degradation of dyes using the ZnO/gCN composites.

Photodegradation Activity of Nitrogen‐rich Graphitic Carbon Nitride Intercalated ZnO\Mg‐Al Layered Double Hydroxide Ternary Nanocomposites on Methylene Blue Dye

“…The N‐carbon acted as a co‐catalyst to improve surface reaction kinetics and the nitrogen species directly contributed to the outstanding photocatalytic activity under visible light irradiation . The kinetics of the MB photocatalytic degradation of the as‐prepared photocatalysts is examined by fitting the kinetic curve to the pseudo‐first‐order process . The plots of ln (C 0 \C) against irradiation time are shown in figure .…”

Strongly Coupled Amorphous Porous NbOx(OH)y/g‐C3N4 Heterostructure Composite for Efficient Photocatalytic Hydrogen Evolution

“…The peaks in the range of 1200–1650 cm −1 can be assigned to aromatic CN heterocycles including stretching of the sp 2 C=N bonds and sp 3 C−N out‐of‐plane bending modes. Moreover, the peaks centered at 804 cm −1 are typical tri‐s‐triazine ring modes . All these peaks coexist in the NbO x (OH) y /CN‐x materials and their intensity decreased with the amount of NbO x (OH) y present in the composites.…”

“…However, its high recombination efficiency of photo‐generated carriers, resulting in a limited hydrogen production rate, is generally regarded as the main drawback that hinders its further applications. To solve this problem, various heterostructure composites containing g‐C 3 N 4 were developed, i. e., ZnO/g‐C 3 N 4 , SnO 2 /g‐C 3 N 4 , TiO 2 /C 3 N 4 , WO 2 /C 3 N 4 , α‐Fe 2 O 3 /C 3 N 4 , Bi 2 O 2 CO 3 /PCN, NiS 2 /g‐C 3 N 4 , Ag–Sr 0.25 H 1.5 Ta 2 O 6 ⋅H 2 O/g‐C 3 N 4 , g‐C 3 N 4 /ZnFe 2 O 4 /Fe 2 O 3 etc . These heterostructure composites indeed facilitated the carriers separation through constructing heterojunctions between g‐C 3 N 4 and other semiconductors, but they usually underwent complicated post‐treatment process, like hydrothermal or calcinating, to create strong interface effects, which is not conducive to further commercial applications.…”

LDH Ternary Nanocomposites: g-C3N4 Intercalated ZnO\Mg-Al for Superior Photocatalytic Activity towards Dye Degradation

“…And also the nitrogen rich surface 2D/2D offers more active surface for the e À transfer. The reaction kinetics of the MB dye degradation of the prepared photocatalysts is investigated by fitting the pseudo-first-order kinetic curve [50].…”