Enhanced photocatalytic activity of AgBr photocatalyst via constructing heterogeneous junctions with reduced graphene

Abstract

A series of rGO/AgBr heterojunction photocatalysts were fabricated through a facile solvothermal method. The rGO/AgBr heterostructures were characterized by XPS, XRD, UV-Vis DRS, SEM, TEM, PL and the transient photocurrent responses. The XRD, SEM, XPS and TEM analyzes indicated that the graphene and silver bromide were successfully compounded without other impurities. The UV-Vis DRS exhibited that the composites have better optical properties than pure silver bromide. The PL and the transient photocurrent responses demonstrated that the addition of graphene significantly promotes the separation of photogenerated electrons and holes. Subsequently, the photocatalytic activities of rGO/AgBr composites were studied by degrading Rhodamine B (RhB). It turned out that the degradation rate of RhB by the rGO/AgBr heterojunction photocatalysts were significantly higher than that by pure AgBr. What's more, to study the photocatalytic degradation mechanism of RhB by rGO/AgBr heterostructures, the trapping experiments were used to identify the main active components. This work confirmed that the photocatalytic degradation performance of the catalyst was greatly improved after doping graphene, which provided certain data support for degradation of organic contaminants in water.

Influence of Synthesis Approach on Controlled Microstructures and Photocatalytic Properties of Ag/AgBr-Activated Carbon Composites on Visible Light Degradation of Tetracycline

“…The addition of IPA had a minimal contribution, while the mixture of all the scavengers highlights the ROS contribution in TC degradation in this study. The ˙O2 − significantly enhanced the TC degradation, which aligned well with previous studies [30,63]; thus, the significant role of superoxide anion radical is further explored in this study. The formation rate of superoxide anion radical (˙O2 − ) through the nitroblue tetrazolium (NBT) photocatalytic degradation conversion into diformazan [64] under visible light irradiation was conducted.…”

“…The addition of IPA had a minimal contribution, while the mixture of all the scavengers highlights the ROS contribution in TC degradation in this study. The ˙O2 − significantly enhanced the TC degradation, which aligned well with previous studies [30,63]; thus, the significant role of superoxide anion radical is further explored in this study. In the scavenging experiment, the degradation rate of TC significantly inhibited around 9-12%, and 29-35%, with the addition of BQ and EDTA-Na2, respectively (Figure 10).…”

Construction of a AgBr–Ag2MoO4 heterojunction and its photocatalytic sterilization activity

“…28 The high-resolution Br 3d spectra show two peaks at 68.40 eV and 69.45 eV that are assigned to Br − in AgBr–Ag 2 MoO 4 . 29 It can be seen that, compared with AgBr and Ag 2 MoO 4 , the Ag peaks of AgBr–Ag 2 MoO 4 move slightly in the direction of lower binding energy, while the Mo and Br peaks move slightly in the direction of higher binding energy, which indicates that electron migration happens. All these results confirmed the successful preparation of a AgBr–Ag 2 MoO 4 heterojunction, which is consistent with the XRD results.…”

One-Pot Synthesis of C@BiOBr for Efficient Photocatalytic Degradation of Phenol

“…On the surface of carbon layer, O 2 is reduced to •O 2 – and then oxidized to 1 O 2 by H 2 O . Meanwhile, since C@BiOBr contains oxygen vacancies, it is easy to enrich electrons at oxygen vacancies, which in turn reduces O 2 to •O 2 – . As a result, a large amount of h + remains on the valence bonds of BiOBr.…”

“…58 Meanwhile, since C@BiOBr contains oxygen vacancies, it is easy to enrich electrons at oxygen vacancies, which in turn reduces O 2 to •O 2 − . 59 As a result, a large amount of h + remains on the valence bonds of BiOBr. All of the produced •O 2 − , 1 O 2 , and h + are effective for the degradation of phenol to CO 2 and H 2 O, realizing the purification of the phenol wastewater.…”