In situ nitrogen-doped hydrophilic mesoporous carbon spheres with different carbon-to-silicon (C/Si) ratios (NMCs-x/3, x = 5, 6, 7, and 8) were prepared by one-step method coupled with a spray drying and carbonizing technique, in which triblock copolymer (F127) and tetraethyl orthosilicate (TEOS) were used as template agents, and biocompatible chitosan (CS) was used as the carbon source and nitrogen source. These carbon materials were characterized by TG, BET, XRD, Raman, FTIR, TEM, XPS, and contact angle measuring device. The adsorption and release properties of mesoporous carbon materials for the poorly soluble antitumor drug hydroxycamptothecin (HCPT) were investigated. Results showed that nanospherical mesoporous carbon materials were successfully prepared with high specific surface area (2061.6 m2/g), narrowly pore size distribution (2.01–3.65 nm), and high nitrogen content (4.75–6.04%). Those NMCs-x showed a satisfactory hydrophilicity, which gradually increased with the increasing of surface N content. And the better hydrophilicity of NMCs-x was, the larger adsorption capacity for HCPT. The absorption capacity of NMCs-x towards HCPT was in the following orders: qNMCs-5/3 > qNMCs-6/3 > qNMCs-7/3 > qNMCs-8/3. NMCs-5/3 had the largest saturated adsorption capacity of HCPT (1013.51 mg g−1) and higher dissolution rate (93.75%).

Hydrogen peroxide (H₂O₂), as a clean and green oxidant, is widely used in many fields. The direct synthesis of H₂O₂ (DSHP) from H₂ and O₂ has attracted most research interest because it relates to a facile, environmentally friendly, and economic process. Yolk–shell Pd-M@HCS (hollow carbon sphere) (M = Co, Ni, Cu) nanocatalysts, in which the bimetal nanoparticle is the core and porous carbon works as the shell layer, are reported in this work. It was found that catalytic activities were enhanced because of the introduced M metals. Additionally, the different mass ratios of Pd to Co (mPd/mCo) were further investigated to improve the catalytic performance for the DSHP. When mPd/mCo was 4.4, the prepared Pd-Co@HCS-(4.4) catalyst, with an average Pd nanoparticle size of 7.30 nm, provided the highest H₂O₂ selectivity of 87% and H₂O₂ productivity of 1996 mmolg_Pd⁻¹·h⁻¹, which were increased by 24% and 253%, respectively, compared to Pd@HCS.