Charge-Directed Nanocellulose Assembly for Interfacial Phase-Transfer Catalysis

Liquid–liquid interfaces present unique opportunities for sustainable biphasic catalysis, yet concurrent amplification of molecular transport and reactivity at these boundaries remains challenging. Here it is demonstrated that high-aspect-ratio cationic nanocellulose (HNC⁺) spontaneously self-assembles into mechanically robust nanomesh architectures at oil-water interfaces through charge-directed assembly. This assembly is driven by electrostatic attraction between the cationic nanofibers and the intrinsic negative charge at hydrophobic-aqueous interfaces (σ ≈−0.3 C m⁻²), generating sufficient excess attractive force (ΔU ≈−1,200 k_BT) to overcome image charge repulsion. The resulting nanomesh exhibits uniform “breathing holes” (≈34 nm) and exceptional stability under extreme conditions (pH 2–13, 1.8 m NaCl, and 90 °C). When applied to oxidative desulfurization, the system achieves >90% thiophene removal under ambient conditions with exceptional atom economy (E-factor < 1.1) and catalyst stability through multiple cycles. This breakthrough strategy for interfacial engineering using renewable materials opens new possibilities for green chemical manufacturing while providing fundamental insights into charge-mediated assembly at liquid interfaces. These findings establish a viable pathway for sustainable heterogeneous catalysis that aligns with circular economy principles.