MnO2 is 2D catalytic and electronic grade semiconducting 2D material. In the bulk form, MnO2 has 1.5 eV predicted band gap while it has been anticipated to increase to 2.0 eV in the monolayer form . Environmentally stable delta (layered) phase of MnO2 has been synthesized using float zone technique at centimeter scales. In its delta-phase, MnO2 crystal structure assumes R-3m phase (see images) which contains layers stacked onto each other vdW bonding. Each layer has three atomic thick arrangement consisting of O-Mn-O layers as shown in the diagram in product images. The material is environmentally stable in air, water, and different gases. Layers can easily exfoliated onto desired substrates with minimal efforts as shown in the product images. Please see our Raman spectrum and comparison to the published literature  in Fig2b.
Inert 2D substrates
Thermodynamically stable catalytic material
Layered Battery applications as a cathode materials