文章信息/Info

Title:

Preparation of g-C3 N4 with Dicyandiamide Assisted by Ammonium Thiocyanate and Its Photocatalytic Performance

文章編號(hào):

1674-3962(2023)06-0514-07

作者:

任學(xué)昌;  時(shí)秋紅;  張玉杰;  楊林海;  張　曦

蘭州交通大學(xué)環(huán)境與市政工程學(xué)院, 甘肅 蘭州 730070

Author(s):

REN Xuechang;  SHI Qiuhong;  ZHANG Yujie;  YANG Linhai;  ZHANG Xi

School of Environmental and Municipal Engineering, Lanzhou Jiaotong University, Lanzhou 730070, China

關(guān)鍵詞:

光催化;  雙氰胺;  硫氰酸銨;  異質(zhì)結(jié);  羅丹明B

Keywords:

photocatalysis;  dicyandiamide;  ammonium thiocyanate;  heterojunction; rhodamine B

分類號(hào):

O643. 36; O644. 1

DOI:

10.7502/j.issn.1674-3962.202105018

文獻(xiàn)標(biāo)志碼:

A

摘要:

以雙氰胺和硫氰酸銨為前驅(qū)體, 將它們按照不同的質(zhì)量比混合, 600 ℃ 高溫煅燒制備g-C3 N4 同型異質(zhì)結(jié)復(fù)合材料光催化劑。采用X 射線衍射儀(XRD)、掃描電鏡(SEM)、透射電鏡(TEM)、傅立葉紅外光譜儀(FTIR)、紫外-可見漫反射吸收光譜儀(UV-vis DRS)等對(duì)制備的材料進(jìn)行了表征分析。以羅丹明B 為模擬污染物, 考察了制備的g-C3N4 在可見光(λ>420 nm)下的催化活性及循環(huán)利用穩(wěn)定性。通過活性物種捕捉實(shí)驗(yàn)探尋其降解機(jī)理, 結(jié)果表明, 雙氰胺與硫氰酸銨按3∶ 2 混合制備的 g-C3 N4 的光催化降解羅丹明B 的效率2 h 達(dá)到了92. 53%, 是純雙氰胺制備的g-C3 N4 的1. 35 倍, 是純硫氰酸銨制備的g-C3 N4的1. 75 倍。以雙氰胺和硫氰酸銨為前驅(qū)體制備的g-C3 N4 是同型異質(zhì)結(jié), 提高了光生載流子的分離效率, 活性物種捕捉實(shí)驗(yàn)表明對(duì)催化活性起主要作用的是超氧自由基(·O2 - )。

Abstract:

Graphite phase carbon nitride heterojunction composites were prepared by calcination at 600 ℃ with dicyandiamide and ammonium thiocyanate as precursor. The materials were characterized by X-ray diffractometer (XRD),scanning electron microscope (SEM), transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FTIR) and UV-visible diffuse reflectance absorption spectrum (UV-vis DRS). The catalytic activity of g-C3N4 under visible light (λ>420 nm) and the recycling stability were investigated using rhodamine B (RhB) as a simulated pollutant. The degradation mechanism was explored by the active species capture experiment. The results showed that the photocatalytic degradation efficiency of g-C3N4 prepared by the mixture of dicyandiamide and ammonium thiocyanate at a ratio of 3∶2 reached 92. 53% in 2 h, which was 1. 35 times that of g-C3N4 prepared by pure dicyandiamide and 1. 75 times that of g-C3N4 prepared by pure ammonium thiocyanate. The g-C3N4 prepared by dicyandiamide and ammonium thiocyanate as precursor is a homotype heterojunction, which improves the separation efficiency of photogenerated carriers. The active species capture experiment showed that the superoxide radical (·O2- ) plays a major role in catalytic activity.