The texture properties of different activated carbons are summarized in Table 1. P-AC presented low BET surface area(892 m2g−1) and small pore volume (1.48 cm3g−1). A significant increase in BET surface area and pore volume was observed when the P-AC was treated by hot water or KOH. PK-AC exhibited higher BET surface area and pore volume than P95-AC. K-AC showed the highest surface area and pore volume. P-AC, P95-AC and PK-AC mainly contained mesopore (Fig. 1 and Table 1). In the case of K-AC, the micropore surface area could achieve 1323 m2g−1, which exceeded its mesopore surface area (1193 m2g−1). In a word, the BET surface areas of the four materials increased according to the sequence: P-AC < P95-AC < PK-AC < K-AC.