Photoelectrochemical Detection with Two-Dimensional Materials

Photoelectrochemical detection harnesses light-induced charge separation at an electrode–electrolyte interface to generate measurable photocurrents in response to analytes of interest. Two-dimensional (2D) materials—including transition metal dichalcogenides, group-III monochalcogenides, elemental monolayers and their heterostructures—offer atomically precise thickness, high surface-to-volume ratio and tunable electronic band structures. These features allow for rapid charge transfer, suppressed recombination of electron–hole pairs and strong light–matter interactions across the ultraviolet, visible and near-infrared spectrum. By engineering band alignment and interfacial chemistry, 2D materials can serve as self-powered photodetectors, selective chemical sensors and bioanalytical platforms with high sensitivity, fast response times and low power consumption. Applications span environmental monitoring of pollutants, non-invasive biomarker assays, wearable health diagnostics and solar-driven water splitting. Recent advances have focused on optimising material synthesis, heterostructure assembly and electrolyte formulation to balance light absorption, charge carrier mobility and stability under operational conditions. Integrating these developments points to a future of compact, versatile sensors that exploit the unique physics of 2D systems for next-generation analytical technologies.

Research from Nature Portfolio

Recent studies have demonstrated an atomically thin photoanode composed of a monolayer indium selenide (InSe) flake encapsulated by monolayer graphene. The InSe layer provides high carrier mobility and intrinsic suppression of electron–hole recombination, while the graphene overlayer ensures robust environmental stability and efficient charge collection. Under visible illumination at standard water-splitting potentials, this heterostructure delivers photocurrent densities exceeding 10 mA cm⁻²—orders of magnitude above previous 2D configurations. Detailed analysis attributes this performance to strong coupling between surface-adsorbed hydroxide ions and photogenerated holes, resulting in persistent photocurrent even after light cessation. This work establishes atomically precise architectures as a powerful platform for investigating interfacial ion kinetics and designing high-efficiency, ultrathin photoelectrodes.

Photoelectrochemical Detection with Two-Dimensional Materials publication trend

The graph below shows the total number of articles in photoelectrochemical detection with two-dimensional materials across all publications each year (not limited to Nature Index journals).

Technical terms

Photoelectrochemical detection: A sensing method in which light absorption at an electrode generates an electrochemical signal proportional to analyte concentration.

Two-dimensional materials: Crystalline solids consisting of single or few atomic layers with strong in-plane bonds and weak out-of-plane interactions.

Heterostructure: A stack or lateral junction of dissimilar 2D materials engineered to tailor electronic band alignment and interfacial charge transfer.

Photoresponsivity: The ratio of photocurrent generated to incident light power, expressed in amperes per watt.

Detectivity: A measure of a detector’s sensitivity, defined as the reciprocal of the noise-equivalent power normalised to detector area and bandwidth (Jones).

Photocurrent density: The electric current per unit area produced by light-induced charge carriers at an electrode surface (mA cm⁻²).

Exfoliation: A process to separate layered materials into individual atomic or few-layer sheets, often via mechanical or liquid-phase methods.

References

1. Atomically thin photoanode of InSe/graphene heterostructure. Nature Communications (2021).
2. Bi2Te3/Bi2Se3/Bi2S3 Cascade Heterostructure for Fast‐Response and High‐Photoresponsivity Photodetector and High‐Efficiency Water Splitting with a Small Bias Voltage. Advanced Science (2022).
3. Performance analysis of photo-electrochemical photodetector based on liquid-phase exfoliation few-layered graphdiyne nanosheets. Nanophotonics (2021).
4. A high-performance “fueled” photodetector based on few-layered 2D ternary chalcogenide NiGa 2 S 4. Journal of Materials Chemistry C (2023).