Recent advances in photoelectrochemical platforms based on porous materials for environmental pollutant detection

Abstract

Human health and ecology are seriously threatened by harmful environmental contaminants. It is essential to develop efficient and simple methods for their detection. Environmental pollutants can be detected using photoelectrochemical (PEC) detection technologies. The key ingredient in the PEC sensing system is the photoactive material. Due to the unique characteristics, such as a large surface area, enhanced exposure of active sites, and effective mass capture and diffusion, porous materials have been regarded as ideal sensing materials for the construction of PEC sensors. Extensive efforts have been devoted to the development and modification of PEC sensors based on porous materials. However, a review of the relationship between detection performance and the structure of porous materials is still lacking. In this work, we present an overview of PEC sensors based on porous materials. A number of typical porous materials are introduced separately, and their applications in PEC detection of different types of environmental pollutants are also discussed. More importantly, special attention has been paid to how the porous material's structure affects aspects like sensitivity, selectivity, and detection limits of the associated PEC sensor. In addition, future research perspectives in the area of PEC sensors based on porous materials are presented.

Fig. 1. Overview of the research contributions in photoelectrochemical sensors since 2010.

Fig. 2. (A) Anodic and cathodic photocurrent generation mechanisms of photoactive material-based electrodes. (B) Different types of PEC sensors with or without the recognition elements.

Fig. 3. Structural effects of photoactive porous materials on the performance of photoelectrochemical detection of environmental pollutants.

Fig. 4. SEM images of (A) TiO₂ NTs and (B) BiOI NFs/TiO₂ NTs. (C) Photocurrent responses of (a) TiO₂ NTs, (b) BiOI NFs/TiO₂ NTs, (c) aptamer/BiOI NFs/TiO₂ NTs, (d) BSA/aptamer/BiOI NFs/TiO₂ NTs, and (e) atrazine/BSA/aptamer/BiOI NFs/TiO₂ NTs. (D) Photocurrent change against atrazine concentrations. Adopted from ref. . Copyright 2021, with permission of Elsevier.

Fig. 5. (A) The preparation of a ZIF-8@ZIS-based PEC sensor for tetracycline. (B) TEM image of ZIF-8@ZIS. (C) The corresponding calibration curve for the photocurrent signal responses toward various concentrations of tetracycline. Adopted from ref. . Copyright 2022, with permission of Elsevier. (D) The synthetic process of hollow CoS_x@CdS composites and the band structures of CoS_x@CdS/HgS composites and charge separation under visible light irradiation. (E) TEM image of CoS_x@CdS composites. (F) Photocurrent responses of the CoS_x@CdS-modified electrodes in the presence of Hg²⁺ of different concentrations. Adopted from ref. . Copyright 2020, with permission of Elsevier.

Fig. 6. (A) Illustration of the TAPP-COF-based PEC sensor for tracing Pb²⁺. (B) The flexible photograph of TAPP-COF thin films. (C) Photocurrent response of the photoelectrochemical detection sensor to different concentrations of Pb²⁺. Adopted from ref. . Copyright 2021, with permission of American Chemical Society. (D) The construction of the F-COF/TiO₂ NTA platform for PEC sensing for dopamine. (E) SEM image of F-COF/TiO₂ NTA. (F) Photocurrent response of F-COF/TiO₂ NTA to different concentrations of dopamine. Adopted from ref. . Copyright 2021, with permission of American Chemical Society.

Fig. 7. (A) TEM image of A-CN. (B) Nitrogen adsorption–desorption isotherm curves for bulk CN and A-CN. (C) Photocurrent responses of bulk CN and A-CN. Adopted from ref. . Copyright 2020, with permission of Elsevier. (D) TEM images of PCN-S. (E) Photocurrent responses of the Au/PCN-S at various oxytetracycline concentrations. (F) The photocurrent generation mechanism of Au/PCN-S under visible light irradiation. Adopted from ref. . Copyright 2018, with permission of Elsevier.

Fig. 8. (A) TEM image of the g-C₃N₄/Ti₃C₂ MXene composite. (B) The transient photocurrents of g-C₃N₄ and g-C₃N₄/Ti₃C₂ MXene composite. (C) The proposed PEC mechanism at the g-C₃N₄/Ti₃C₂ MXene composite. Adopted from ref. . Copyright 2021, with permission of Elsevier. (D) SEM image of AgI/Ti₃C₂ MXene/GO composite. (E) The photocurrent responses of Ti₃C₂ MXene/GO, AgI/Ti₃C₂ MXene/GO, and Ag₂S/AgI/Ti₃C₂ MXene/GO composites. (F) The possible electron-transfer mechanism of the AgI/Ti₃C₂ MXene/GO composite. Adopted from ref. . Copyright 2023, with permission of Elsevier.

Fig. 9. (A) The mechanism of sensing Hg²⁺ with the photoelectrochemical method. (B) The photocurrent responses of BiVO₄ and Ti₃C₂ MXene/BiVO₄. Adopted from ref. . Copyright 2020, with permission of Elsevier. (C) TEM and HR-TEM images of Cu₂O–CuO–TiO₂ composites. (D) Nitrogen adsorption–desorption isotherms of the Cu₂O–CuO–TiO₂. (E) Photocurrent responses with different Pb²⁺ concentrations. Adopted from. Copyright 2022, with permission of Elsevier.

Fig. 10. (A) The illustration of the PEC ampicillin apta-sensor based on the BiFeO₃/utg-C₃N₄ composite. (B) The photocurrent signals of (a) utg-C₃N₄, (b) BiFeO₃, (c) BiFeO₃/bulk-C₃N₄, and (d) BiFeO₃/utg-C₃N₄. (C) Photocurrent responses of the as-prepared apta-sensor at various ampicillin concentrations. Adopted from ref. . Copyright 2019, with permission of Elsevier. (D) SEM image of the ZnO/g-C₃N₄ composite. (E) The transient photocurrent responses of (a) g-C₃N₄, (b) ZnO, and (c) ZnO/g-C₃N₄. (F) Electron transfer mechanism for ZnO/g-C₃N₄. Adopted from ref. . Copyright 2023, with permission of Elsevier. (G) TEM images of SnO₂-Au NPs. (H) The photocurrent responses of SnO₂-Au NPs with different concentrations of nitrite. (I) The possible mechanism of PEC sensing nitrite. Adopted from ref. . Copyright 2020, with permission of Elsevier.

Shiben Liu

Jinhua Zhan

Bin Cai