Activated
carbon fibers (ACFs) with high adsorption performance and mechanical
strength are one of the essential materials to meet the needs of industrial
gas adsorption. The activation step is the most critical step affecting
the performance of ACFs. This study presents a facile one-step carbonization
and activation method for preparing activated carbon fibers with a
phenolic fiber as a carbonaceous precursor, followed by CuCl2 as an activating agent. The prepared activated carbon fiber (ACF-0.1)
has three main advantages that are high microporosity of 89%, less
use of an activator (mass ratio of PF and CuCl2 was 1:0.1),
and excellent mechanical properties. In particular, taking advantage
of ultra-micropores (<1 nm) created by low-dose CuCl2, activated carbon fibers can be used well as solid adsorbents for
the CO2 capture, which show a high selectivity of 22.3
(calculated by IAST) and valid separation performance at 298 K and
0.15 bar. Meanwhile, the activated carbon fibers with developed micropores
created by high-dose CuCl2 exhibit an active role in gas-phase
toluene adsorption. In addition, the activated carbon fibers have
considerable flexibility and outstanding mechanical strength, which
is nearly 3 times as high as the commercial rayon-based fibers. This
method is significant in producing high-performance activated carbon
fibers for adsorption in practical engineering applications.