The use of precious metals in many areas, such as printed circuit boards, catalysts, and targeted drugs, is increasing due to their unique physical and chemical properties, but their recovery remains a great challenge. Here, we report a sandwiched Ti 3 C 2 T x MXene/carbon nanotube (CNT) hybrid membrane, where the CNT isolates and supports the MXene sheets, which act as a reducing agent. The hybrid membrane shows excellent ability to capture precious metal ions in solution with a high flux. The water permeability of the membrane reaches 437.6 L m −2 h −1 bar −1 (2.46 × 10 −18 m 2 ), about 202 times higher than that of a pure Ti 3 C 2 T x membrane, and captures 99.8% Au(III) from a solution with an extremely low concentration of 20 ppm. The desirable precious metal trapping capability of the Ti 3 C 2 T x −CNT film is due to the high redox activity of C−Ti−OH. This work provides an efficient way for the recovery of precious metal ions from wastewater.

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Noble‐metal free, cost‐effective, and highly stable catalysts with efficient activity for both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) have attracted tremendous research interest in recent years. Here, a flexible, self‐standing hybrid film comprising a N‐doped single‐wall carbon nanotube (SWCNT) network on which are anchored Ni nanoparticles encapsulated by a monolayer of N‐doped carbon (NCNi) is reported. The films are prepared by floating catalyst chemical vapor deposition followed by NH 3 treatment. The material obtained at optimum conditions shows excellent bifunctional electrocatalytic activity in alkaline media with low overpotentials of 190 and 270 mV for HER and OER, respectively, to reach a current density of 10 mA cm −2 . A current density of 10 mA cm −2 at 1.57 V is achieved when this freestanding and binder‐free rod‐shaped NCNi/SWCNT assembly is used as cathode and anode in 1 m KOH solution for overall water splitting, presenting one of the best values reported to date.

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