High‐Performance Boiling Surfaces Enabled by an Electrode‐Transpose All‐Electrochemical Strategy

High-performance boiling surfaces are in great demand for efficient cooling of high-heat-flux devices. Although various micro-/nano-structured surfaces have been engineered toward higher surface wettability and wickability for enhanced boiling, the design and fabrication of surface structures for realizing both high critical heat flux (CHF) and high heat transfer coefficient (HTC) remain a key challenge. Here, a novel "electrode-transpose" all-electrochemical strategy is proposed to create superhydrophilic microporous surfaces with higher dendrites and larger pores by simply adding an electrochemical etching step prior to the multiple electrochemical deposition steps. Enabled by the high nucleation density and high wicking capability, a high boiling performance is shown on such "etching-then-deposition" surfaces with simultaneously high CHF of 2,641 ± 10 kW m^-2 and high HTC of 214 ± 6 kW (m² K)^-1, which are more than 2.5 and 4.3-fold enhanced from those on smooth surfaces, respectively. A very stable morphology and boiling performance of such surfaces subject to consecutive tests are also shown. Using this strategy, such superhydrophilic microporous layers are fabricated on curved surfaces with larger areas, both on spheres and slender cylinders, and demonstrate excellent boiling performance in quenching tests. This facile, geometry-adaptive, durable, and scalable strategy is very promising for making high-performance boiling surfaces for large-scale industrial applications.