Biochar(BC)-supported nanoscaled zinc oxide (nZO) was encapsulated either with (nZORc/BC) or with no (nZOR/BC) sodium carboxymethyl cellulose (CMC). The X-ray diffraction and ultraviolet (UV)-visible-near infrared spectrophotometry revealed that nZO of 16, 10, and 20 nm with energy band gaps of 2.79, 3.68 and 2.62 eV were synthesized for nZOR/BC, nZORc/BC and nZO/BC, respectively. The Langmuir isotherm predicted saturated sorption of methylene blue (MB) was 17.01 g kg⁻¹ for nZORc/BC, over 19 times greater than nZOR/BC and nZO/BC. Under UV irradiation, 10.9, 61.6, 83.1, and 41.6% of MB were degraded for nZORc/BC, nZO/BC, nZOR/BC and BC. The scavenging experiment revealed hydroxyl radical dominated CMC degradation. Exogenous CMC (2 g L⁻¹) increased MB sorption from 10.6% to 73.1%, but decreased MB degradation from 80.7% to 41.1%, relative to nZOR/BC. Thus, CMC could increase MB sorption by electrostatic attraction and other possible mechanisms. The compromised MB degradation may be ascribed to reduced availability of hydroxyl and superoxide radicals to degrade MB, and increased band gap energy of ZnO.

用（nZORc / BC）或不使用（nZOR / BC）羧甲基纤维素钠（CMC）封装Biochar（BC）支撑的纳米级氧化锌（nZO）。X射线衍射和紫外可见近红外分光光度法显示，合成了16、10和20 nm的nZO，能带隙为2.79、3.68和2.62 eV，用于nZOR / BC，nZORc / BC和nZO / BC。Langmuir等温线预测的nZORc / BC的亚甲基蓝（MB）饱和吸附为17.01 g kg ^-1，是nZOR / BC和nZO / BC的19倍以上。在紫外线照射下，nZORc / BC，nZO / BC，nZOR / BC和BC分别降解了10.9、61.6、83.1和41.6％的MB。清除实验表明，羟自由基主导了CMC的降解。外源CMC（2 g L ^-1）相对于nZOR / BC，MB吸附量从10.6％增加到73.1％，但MB降解率从80.7％减少到41.1％。因此，CMC可以通过静电吸引和其他可能的机制来增加MB的吸附。受损的MB降解可能归因于羟基和超氧化物自由基降解MB的可用性降低，以及ZnO的带隙能增加。