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Highly ordered mesoporous crystalline Mo-doped WO2 (Mo x W1–x O2: 1 > x > 0.08) materials with different molybdenum contents were synthesized via a nanocasting strategy using mesoporous silica KIT-6 as a hard template. The presence of molybdenum significantly increased the rate of reduction of tungsten trioxide to tungsten dioxide using hydrogen gas as the reducing agent, and it also prevented the dioxide product from being further reduced to zerovalent metal tungsten. This molybdenum doping strategy provides a new solution for the synthesis of WO2-based materials with well-defined nanostructures. The obtained mesoporous Mo0.14W0.86O2 material possessed a metallic conductivity (0.8 Ω cm, 300 K) and a high tap density of 3.6 g cm–3. This material exhibits a high and reversible lithium storage capacity of 635 mAh g–1 and is stable up to at least 70 cycles without noticeable fading.

Flexible paper electrodes for supercapacitors were prepared with partially-exfoliated graphite and polypyrrole as the active materials. Graphite was coated on paper with pencil drawing and then electrochemically exfoliated using the cyclic voltammetry (CV) technique to obtain the exfoliated graphite (EG)-coated paper (EG-paper). Polypyrrole (PPy) doped with β-naphthalene sulfonate anions was deposited on EG-paper through in-situ polymerization, leading to the formation of PPy-EG-paper. The as-prepared PPy-EG-paper showed a high electrical conductivity of 10.0 S·cm −1 and could be directly used as supercapacitor electrodes. The PPy-EG-paper electrodes gave a remarkably larger specific capacitance of 2148 F·g −1 at a current density of 0.8 mA·cm −2 , compared to PPy-graphite-paper (848 F·g −1 ). The capacitance value of PPy-EG-paper could be preserved by 80.4% after 1000 charge/discharge cycles. In addition, the PPy-EG-paper electrodes demonstrated a good rate capability and a high energy density of 110.3 Wh·kg −1 at a power density of 121.9 W·kg −1 . This work will pave the way for the discovery of efficient paper-based electrode materials.