Nitrogen-doped titanium dioxide (N/TiO₂) nanophotocatalysts were successfully synthesized in the presence of environmentally benign nitrogen dopant source, guanidinium chloride, by the sol-gel method. The effect of calcination temperature (300–600 °C) on their physicochemical properties was investigated by means XRD, XPS, FESEM, HRTEM, Raman spectroscopy, UV-vis DRS, PL and BET. Moreover, their photocatalytic activities were evaluated against rhodamine B (RhB) degradation under direct sun light. Results showed that the crystal phase of spheroidal N/TiO₂ nanoparticles was changed from anatase (300 °C) to rutile (600 °C) via an intermediate anatase/rutile (A/R) mixed phase (400–500 °C), and the RhB photodegradation performance was increased with the decrease of the calcination temperature. Notably, N/TiO2 prepared at 400 °C demonstrated the best degradation performance (99%) after 5 h irradiation. The enhanced performance with high photostability was mainly attributed to its higher surface area and pore volume, stronger light absorption, and lower recombination rate. Such nanomaterials have practical applications for environmental remediation.

通过溶胶-凝胶法在环境友好的氮掺杂源氯化胍的存在下成功合成了氮掺杂的二氧化钛（N / TiO ₂）纳米光催化剂。通过XRD，XPS，FESEM，HRTEM，拉曼光谱，UV-vis DRS，PL和BET研究了煅烧温度（300–600°C）对其理化性质的影响。此外，评估了它们在日光直射下对若丹明B（RhB）降解的光催化活性。结果表明，球状N / TiO ₂的晶相纳米颗粒通过中间的锐钛矿/金红石（A / R）混合相（400-500°C）从锐钛矿（300°C）变为金红石（600°C），RhB的光降解性能随着煅烧温度。值得注意的是，在400°C下制备的N / TiO2辐照5 h后表现出最佳的降解性能（99％）。具有高光稳定性的增强性能主要归因于其更高的表面积和孔体积，更强的光吸收性以及更低的重组率。这样的纳米材料在环境修复方面具有实际应用。