Electronic and electrocatalytic applications based on solution-processed two-dimensional platinum diselenide with thickness-dependent electronic properties

Platinum diselenide (PtSe₂) has shown great potential as a candidate two-dimensional (2D) material for broadband photodetectors and electrocatalysts because of its unique properties compared to conventional 2D transition metal dichalcogenides. Synthesis of 2D PtSe₂ with controlled layer number is critical for engineering the electronic behavior to be semiconducting or semimetallic for targeted applications. Electrochemical exfoliation has been investigated as a promising approach for mass-producing in a cost-effective manner, but obtaining high-quality films with control over electronic properties remains difficult. Here, we demonstrate wafer-scale 2D PtSe₂ films with pre-determined electronic types based on a facile solution-based strategy. Semiconducting or semimetallic PtSe₂ nanosheets with large lateral sizes are produced via electrochemically driven molecular intercalation, followed by centrifugation-based thickness sorting. Finally, gate-tunable broadband visible and near-infrared photodetector arrays are realized based on semiconducting PtSe₂ nanosheet films, while semimetallic films are used to create catalytic electrodes for overall water splitting with long-term stability.