Preparation of TiO2-g-C3N4 composites and its application in cement stone surface
-
摘要: 以Ti(SO4)2和尿素为原料,采用均匀沉淀法及不同煅烧温度制备了TiO2-g-C3N4复合材料。利用XRD和SEM对g-C3N4和TiO2-g-C3N4复合材料的结构及形貌进行了表征,并以模拟太阳光为光源,甲基橙为目标降解物,对其光催化活性进行了研究。将高催化性能的TiO2-g-C3N4复合材料与水泥石表面结合制备了具有光催化性能的水泥石。结果表明:在300℃和400℃条件下煅烧制备的TiO2-g-C3N4复合材料具有牢固异质结,而在500℃条件下煅烧产生N掺杂的TiO2。其中400℃条件下煅烧所得TiO2-g-C3N4复合材料的光催化性能最好,模拟太阳光光照60 min降解率达到91%。通过拟合计算,发现400℃条件下TiO2-g-C3N4复合材料的光催化速率最快。与400℃ TiO2-g-C3N4复合材料结合的水泥石也具有较好的光催化降解性能,模拟太阳光光照240 min降解率可达到90%以上,TiO2-g-C3N4复合材料在400°C可以降低水泥石的初凝终凝时间,并提高其抗压强度。Abstract: The TiO2-g-C3N4 composites were prepared by a uniform precipitation method and the structure and morphology were characterized for g-C3N4 and TiO2-g-C3N4 composites by XRD and SEM. The photocatalytic activity of the as-prepared sample was evaluated by degradation of methyl orange under simulated sunlight. The composites with high catalytic performance were combined with the cement stone surface to obtain the photocatalytic cement stone. The results show that the TiO2-g-C3N4 composites prepared at 300℃ and 400℃ have strong heterojunctions, and N-doped TiO2 was produced at 500℃. The best photocatalytic activity of TiO2-g-C3N4 composites was obtained at 400℃, and the degradation rate reaches 91% under the simulated sunlight for 60 min. By fitting calculation, it is found that the photocatalytic rate of TiO2-g-C3N4 composites obtained at 400℃ is the fastest. The cement stone combined with the TiO2-g-C3N4 composites obtained at 400℃ still have good catalytic degradation performance, and the degradation rate can reach more than 90% under the simulated sunlight for 240 minutes. The TiO2-g-C3N4 composites can reduce the initial setting and final setting time of the cement stone at 400°C and improve its compressive strength.
-
Key words:
- temperature /
- TiO2-g-C3N4 /
- heterojunctions /
- photocatalytic activity /
- cement stone /
- compressive strength
-
表 1 不同煅烧温度下制备的TiO2-g-C3N4复合材料样品编号
Table 1. Sample numbers of TiO2-g-C3N4 composite powders prepared at different calcination temperatures
Sample Ti(SO4)2/g Temperature/℃ g-C3N4/g CO(NH2)2/g H2O/mL TiO2-g-C3N4-3 1.2 300 0.46 0.9 20 TiO2-g-C3N4-4 1.2 400 0.46 0.9 20 TiO2-g-C3N4-5 1.2 500 0.46 0.9 20 表 2 TiO2、g-C3N4和不同煅烧温度下TiO2-g-C3N4复合材料的拟合方程
Table 2. Fitting equations of TiO2, g-C3N4 and TiO2-g-C3N4 composite powders at different calcination temperatures
Sample Fitting equation k R2 TiO2 ${\rm In}({C_t}/{C_0}) = - 0.0009t - 0.2183$ −0.0009 0.977 g-C3N4 ${\rm In}({C_t}/{C_0}) = - 0.0244t + 1.1728$ −0.0244 0.994 TiO2-g-C3N4-3 ${\rm In}({C_t}/{C_0}) = - 0.0290t + 0.004$ −0.0290 0.998 TiO2-g-C3N4-4 ${\rm In}({C_t}/{C_0}) = - 0.0305t - 0.183$ −0.0305 0.993 TiO2-g-C3N4-5 ${\rm In}({C_t}/{C_0}) = - 0.0133t + 0.0259$ −0.0133 0.990 Photocatalytic cement stone ${\rm In}({C_t}/{C_0}) = - 0.001t - 0.2135$ −0.001 0.989 Notes: k—Slope of straight line ; R2—Goodness of fit. 表 3 TiO2-g-C3N4-4复合材料光催化水泥石和普通硅酸盐力学性能
Table 3. Mechanical properties of TiO2-g-C3N4-4 composite photocatalytic cement stone and common silicate
Cement based material Initial setting time/min Final setting time/min Compressive strength/MPa P·O42.5 549 691 28.2 Photocatalytic cement based 518 663 33.7 -
[1] 刘刚, 韩立娟, 陈作雁, 等. V-N共掺杂TiO<sub>2</sub>/玻璃珠光催化复合材料的制备及光催化性能[J]. 复合材料学报, 2017, 34(5):1062-1068.LIU G, HAN L J, CHEN Z Y, et al. Preparation and photocatalytic properties of V-N co-doped TiO<sub>2</sub>/glass beads photocatalytic composite[J]. Acta Materiae Compositae Sinica,2017,34(5):1062-1068(in Chinese). [2] DU D, SHI W, WANG L, et al. Yolk-shell structured Fe<sub>3</sub>O<sub>4</sub>@void@TiO<sub>2</sub> as a photo-Fenton-like catalyst for the extremely efficient elimination of tetracycline[J]. Applied Catalysis B: Environmental,2017,200:484-492. doi: 10.1016/j.apcatb.2016.07.043 [3] 于艳, 姚秉华, 杨帆, 等. TiO<sub>2</sub>-ZnO复合中空微球的制备及光催化性能[J]. 复合材料学报, 2019, 36(1):206-212.YU Y, YAO B H, YANG F, et al. Preparation and photocatalytic properties of TiO<sub>2</sub>-ZnO composite hollow microspheres[J]. Acta Materiae Compositae Sinica,2019,36(1):206-212(in Chinese). [4] QI K Z, CHENG B, YU J G, et al. A review on TiO<sub>2</sub>-based Z-scheme photocatalysts[J]. Chinese Journal of Catalysis,2017,38(12):1936-1955. [5] 王佳忆, 王学江, 黄嘉瑜, 等. Br-N共掺杂TiO<sub>2</sub>/ 磁性炭复合材料的制备及其可见光催化性能[J]. 复合材料学报, 2017, 34(4):890-898.WANG J Y, WANG X J, HUANG J Y, et al. Preparation and photocatalytic performance of Br-N codoped TiO<sub>2</sub>/magnetic carbon composites[J]. Acta Materiae Compositae Sinica,2017,34(4):890-898(in Chinese). [6] 李燕, 孙宝, 那泽生, 等. TiO<sub>2</sub>/偏高岭土复合粉制备及其光催化性能研究[J]. 非金属矿, 2019, 42(3):79-82. doi: 10.3969/j.issn.1000-8098.2019.03.022LI Y, SUN B, NA Z S, et al. Study on preparation of TiO<sub>2</sub>/Metakaolin composite powder and its photocatalytic properties[J]. Non-metallic Mines,2019,42(3):79-82(in Chinese). doi: 10.3969/j.issn.1000-8098.2019.03.022 [7] ZHU Y, ZHANG Z, LU N, et al. Prolonging charge-separation states by doping lanthanideions into {001}/{101}facets-coexposed TiO<sub>2</sub> nanosheets for enhancing photocatalytic H<sub>2</sub> evolution[J]. Chinese Journal of Catalysis,2019,40(03):413-423. doi: 10.1016/S1872-2067(18)63182-1 [8] JIANG H L, LIU J, LI M L, et al. Facile synthesis of C-decorated Fe, N co-doped TiO<sub>2</sub> with enhanced visible-light photocatalytic activity by a novel co-precursor method[J]. Chinese Journal of Catalysis,2018,39(4):747-759. doi: 10.1016/S1872-2067(18)63038-4 [9] ADAMU H, MCCUE A J, TAYLOR R S F, et al. Simultaneous photocatalytic removal of nitrate and oxalic acid over Cu<sub>2</sub>O/TiO<sub>2</sub>, and Cu<sub>2</sub>O/TiO<sub>2</sub>-AC composites[J]. Applied Catalysis B: Environmental,2017,217:181-191. doi: 10.1016/j.apcatb.2017.05.091 [10] NING X, LI J, YANG B, et al. Inhibition of photocorrosion of CdS via assembling with thin film TiO<sub>2</sub> and removing formed oxygen by artificial gill for visible light overall water splitting[J]. Applied Catalysis B: Environmental,2017,212:129-139. doi: 10.1016/j.apcatb.2017.04.074 [11] LI Y, WANG P, HUANG C, et al. Synthesis and photocatalytic activity of ultrafine Ag<sub>3</sub>PO<sub>4</sub> nano-particles on oxygen vacated TiO<sub>2</sub>[J]. Applied Catalysis B: Environmental,2017,205:489-497. doi: 10.1016/j.apcatb.2016.12.059 [12] 孙志明, 李雪, 马建宁, 等. 类石墨氮化碳/伊利石复合材料的制备及其可见光催化性能[J]. 复合材料学报, 2018, 35(6):204-211.SUN Z M, LI X, MA J N, et al. Preparation of g-C<sub>3</sub>N<sub>4</sub>/illite composite and its visible-light-driven photocatalytic activity[J]. Acta Materiae Compositae Sinica,2018,35(6):204-211(in Chinese). [13] 周银, 张平, 邹赛, 等. 可磁分离 Fe<sub>3</sub>O<sub>4</sub>/C<sub>3</sub>N<sub>4</sub>复合材料的制备及其性能[J]. 复合材料学报, 2018, 35(11):3189-3195.ZHOU Y, ZHANG P, ZOU S, et al. Preparation and properties of magnetic separation Fe<sub>3</sub>O<sub>4</sub>/C<sub>3</sub>N<sub>4</sub> composites[J]. Acta Materiae Compositae Sinica,2018,35(11):3189-3195(in Chinese). [14] LI F, YU Z, SHI H, et al. A mussel-inspired method to fabricate reduced graphene oxide/g-C<sub>3</sub>N<sub>4</sub>, composites membranes for catalytic dec- omposition and oil-in-water emulsion separation[J]. Chemical Engineering Journal,2017,322:33-45. doi: 10.1016/j.cej.2017.03.145 [15] LU Z, ZENG L, SONG W, et al. In situ synthesis of C-TiO<sub>2</sub>-g-C<sub>3</sub>N<sub>4</sub> heterojunction nanocomposite as highly visible light active photocatalyst originated from effective interfacial charge transfer[J]. Applied Catalysis B Environmental,2017,202:489-499. doi: 10.1016/j.apcatb.2016.09.052 [16] CHEN X, WEI J, HOU R, et al. Growth of g-C<sub>3</sub>N<sub>4</sub> on mesoporous TiO<sub>2</sub> spheres with high photocatalytic activity under visible light irradiation[J]. Applied Catalysis B: Environmental,2016,188:342-350. doi: 10.1016/j.apcatb.2016.02.012 [17] LU L, WANG G, ZOU M, et al. Effects of calcining temperature on formation of hierarchical TiO<sub>2</sub>-g-C<sub>3</sub>N<sub>4</sub> hybrids as an effective Z-scheme heterojunction photocatalyst[J]. Applied Surface Science,2018,441:1012-1023. doi: 10.1016/j.apsusc.2018.02.080 [18] NIU P, ZHANG L, LIU G, et al. Graphene-like carbon nitride nanosheets for improved photocatalytic activities[J]. Advanced Functional Materials,2012,22:4763-4770. doi: 10.1002/adfm.201200922 [19] 何军辉, 姚武. 沸石及水泥基材料二次负载TiO<sub>2</sub>的光催化性能[J]. 建筑材料学报, 2020, 23(1):35-39.HE J H, YAO W. Photocatalytic performance of secondarily loading TiO<sub>2</sub> with zeolite and cement based materials[J]. Journal of Building Materials,2020,23(1):35-39(in Chinese). [20] 鲁浈浈, 刘栋, 张琪, 等. 负载氮化碳光催化混凝土的制备及性能表征[J]. 建筑材料学报, 2019, 22(4):559-566,583.LU Z Z, LIU D, ZHANG Q, et al. The preparation and characterization of photocatalytic concrete loaded with carbon nitride for degradation of automobile exhaust[J]. Journal of Building Materials,2019,22(4):559-566,583(in Chinese). [21] 徐名凤, 施惠生, 吴凯. TiO<sub>2</sub>光催化水泥基材料去除氮氧化物研究进展[J]. 新型建筑材料, 2019, 46(5):46-49, 53. doi: 10.3969/j.issn.1001-702X.2019.05.012XU M F, SHI H S, WU K. Research development of photocatalytic NOx abatement by TiO<sub>2</sub>-cementitious composites[J]. New Building Materials,2019,46(5):46-49, 53(in Chinese). doi: 10.3969/j.issn.1001-702X.2019.05.012 [22] 张华森, 李喜宝, 冯志军, 等. 加热温度对尿素水溶液制备类石墨相氮化碳的影响及其机理[J]. 硅酸盐学报, 2018, 46(02):281-287.ZHANG H S, LI X B, FENG Z J, et al. Effect of heating temperature on preparation of graphite-like g-C<sub>3</sub>N<sub>4</sub> by pyrolysis of urea aqueous solution and its mechanism[J]. Journal of The Chinese Ceramic Society,2018,46(02):281-287(in Chinese). [23] ZHANG G, ZHANG T, LI B, et al. An ingenious strategy of preparing TiO<sub>2</sub>-g-C<sub>3</sub>N<sub>4</sub> heterojunction photocatalyst: In situ growth of TiO<sub>2</sub> nanocrystals on g-C<sub>3</sub>N<sub>4</sub> nanosheets via impregnation-calcination method[J]. Applied Surface Science,2018,19(23):2012-4. [24] WANG H, YUAN X Z, WU Y, et al. Synthesis and applications of novel graphitic carbon nitride/metal-organic frameworks mesoporous photocatalyst for dyes removal[J]. Applied Catalysis B: Environmental,2015,174-175:445-454. [25] YU Y, GENG J, LI H, et al. Exceedingly high photocatalytic activity of g-C<sub>3</sub>N<sub>4</sub>/Gd-N-TiO<sub>2</sub> composite with nanoscale heterojunctions[J]. Solar Energy Materials and Solar Cells,2017,168:91-99. doi: 10.1016/j.solmat.2017.04.023 [26] SHEN G D, PU Y P, CUI Y F, et al. Easy synthesis of TiO<sub>2</sub>-g-C<sub>3</sub>N<sub>4</sub> heterostructure photocatalyst with large surface area and excellent photocatalytic Activity[J]. Ceramics International,2017,43:664-670.