A collaborative team led by Prof. Yi Xiong from Wuhan Textile University, Prof. Wei Zeng from Anhui University, and Prof. Shuo Jin from the Institute of High Energy Physics, Chinese Academy of Sciences, has proposed a hierarchically converged defect-engineering restoration strategy. By implementing this approach, the researchers constructed a multidimensional ZnO/Bi₂O₃/BiOCl/BP/MXene heterojunction photoelectrode framework, achieving highly sensitive photoelectrochemical-electrostatic dual-mode sensing.
The work, entitled
“Hierarchically Converged Defect Engineering with Sequential 2D Black Phosphorus/MXene Heterostructures for Sensitive Photoelectrochemical–Electrostatic Coupled Sensors”, was published in
Research (2025, Volume 8). DOI:
https://doi.org/10.34133/research.0966
- Research Background
Multifunctional sensors have found widespread applications in health monitoring, environmental perception, and intelligent electronics. Among them, photoelectrochemical (PEC) sensors and electrostatic field sensors have attracted considerable attention owing to their ultrahigh sensitivity, particularly for the detection of bioelectrical signals such as surface electromyography (sEMG). However, conventional electrodes typically suffer from weak signal intensity, poor long-term stability, and limited biocompatibility, which severely hamper their practical deployment. Precisely tailoring the microstructure and energy-level alignment of two-dimensional material-based heterojunction devices, thereby synergistically harnessing photoelectrochemical and electrostatic coupling effects, remains a critical challenge in the development of next-generation intelligent sensors.
2. Key Innovations
Herein, we propose a hierarchically converged defect-engineering restoration strategy to construct a multidimensional ZnO/Bi₂O₃/BiOCl/BP/MXene heterojunction photoelectrode framework (Fig. 1). By sequential incorporation of two-dimensional black phosphorus (BP) and MXene nanosheets, nanoporous defects within the pristine three-dimensional BiOCl scaffold were precisely repaired. This targeted modulation dramatically increased the electrochemically active surface area, optimized interfacial energy-level alignment, and established efficient carrier transport pathways, thereby substantially enhancing the synergistic photoelectrochemical–electrostatic coupling performance (Fig. 2).
As shown in Figure 3, high-resolution transmission electron microscopy (HRTEM), fast Fourier transform (FFT), and energy-dispersive X-ray spectroscopy (EDX) analyses intuitively reveal the embedding of black phosphorus (BP) within the ZnBiP heterostructure and its associated defect repair mechanism. At the atomic scale, these characterizations confirm that BP not only fills pore defects in the three-dimensional heterostructure framework but also forms stable interfacial structures via Bi–O–P chemical bonds, thereby providing a microstructural foundation for the enhanced photoelectrochemical performance.
Key achievements include:
- A photocurrent density of 20.46 μA cm⁻² under 30 W blue light, 2.4 times higher than the structure without 2D layers;
- A synergistic light-AEF effect that further enhances carrier transport and detection sensitivity;
- The stability assessment of the ZnBiPM electrode under light irradiation exceeded 1000 cycles (total 10,000 seconds, with a switching period of 10 seconds), and the electrode could achieve 84.86% of the initial photocurrent (Figure 4);
- A light-assisted sEMG sensor with 30–40% signal enhancement under illumination (Figure 5).
3.Significance and Future Applications
This work not only proposes a novel hierarchical convergence strategy for defect engineering and repair, but also demonstrates the remarkable potential of light–electrostatic-field coupling in amplifying bioelectrical signal detection. The developed sensor holds immense promise for applications in wearable health monitoring, human–machine interfaces, and flexible electronics. Future efforts will focus on further optimizing the device architecture of 2D-material-based systems, improving energy-level alignment, and enhancing long-term stability, thereby accelerating their translation into clinical diagnostics and intelligent rehabilitation technologies.
The complete study is accessible via DOI:10.34133/research.0966