發(fā)布時(shí)間：2019-05-23 22:25

【摘要】：近年來,環(huán)境污染問題日益嚴(yán)重。由重金屬離子引起的環(huán)境污染問題已經(jīng)被全世界所關(guān)注了。重金屬離子進(jìn)入水體后,會對水體中的生物造成嚴(yán)重危害,并會通過食物鏈影響人體的健康。因此,正確處理水體中的重金屬離子對水資源的保護(hù)和人類的健康都是十分有意義的。我們通過簡單的溶膠-凝膠法及水熱法合成了三維核殼結(jié)構(gòu)的Fe3O4/MgSiO3亞微球,其內(nèi)核是Fe3O4亞微球,外殼是MgSiO3。將合成好的Fe3O4/MgSiO3亞微球應(yīng)用于吸附水溶液中重金屬離子U(Ⅵ)的實(shí)驗(yàn)。并討論了溶液pH值、離子強(qiáng)度、吸附劑濃度、溫度等因素對U(Ⅵ)吸附實(shí)驗(yàn)的影響。實(shí)驗(yàn)結(jié)果表明,U(Ⅵ)在Fe3O4/MgSiO3亞微球上的吸附受pH值、離子強(qiáng)度的影響很大。通過計(jì)算得知,U(Ⅵ)在 Fe3O4/MgSiO3亞微球上的最大吸附量達(dá)到了242.1mg/g。合成的亞微球材料顯示了其在去除重金屬離子領(lǐng)域的應(yīng)用前景。在溫和的條件下,通過簡單的化學(xué)浴方法合成了三維分層的CdS/α-Fe2O3異質(zhì)結(jié)納米復(fù)合物。CdS/α-Fe2O3的光譜響應(yīng)范圍很寬,在可見光照射下,我們將其應(yīng)用到光催化還原Cr(Ⅵ)的實(shí)驗(yàn)中。我們研究了CdS與α-Fe2O3的摩爾比率對復(fù)合物晶型、微觀結(jié)構(gòu)、光吸收特性及光催化還原Cr(Ⅵ)的影響。結(jié)果表明,當(dāng)CdS的含量適中時(shí)(Fe原子與Cd原子的摩爾比率為1.25：3),CdS/α-Fe2O3光催化還原Cr(Ⅵ)的效率最高,而且合成的CdS/α-Fe2O3穩(wěn)定性最好。CdS納米顆粒緊密接觸α-Fe2O3微米花并在界面處形成了異質(zhì)結(jié)構(gòu),這可能是CdS/α-Fe2O3復(fù)合物光催化活性高的原因。這些異質(zhì)結(jié)構(gòu)可以有效地促進(jìn)光生電子-空穴對的分離,進(jìn)而提高CdS/α-Fe2O3的光催化還原效率。
[Abstract]:In recent years, the problem of environmental pollution is becoming more and more serious. The environmental pollution caused by heavy metal ions has been paid more and more attention all over the world. When heavy metal ions enter the water body, it will cause serious harm to the organisms in the water body, and will affect the health of the human body through the food chain. Therefore, it is very meaningful to correctly deal with the protection of water resources and human health by correctly dealing with heavy metal ions in water bodies. Fe3O4/MgSiO3 submicrospheres with three-dimensional core-shell structure were synthesized by simple sol-gel method and hydrothermal method. The core of the microspheres was Fe3O4 submicrospheres and the shell was MgSiO3.. The synthesized Fe3O4/MgSiO3 submicrospheres were applied to the adsorption of heavy metal ions U (VI) in aqueous solution. The effects of pH value, ion strength, absorbent concentration and temperature on U (VI) adsorption experiment were also discussed. The experimental results show that the adsorption of, U (VI) on Fe3O4/MgSiO3 submicrospheres is greatly affected by pH value and ion strength. The maximum adsorption capacity of, U (VI) on Fe3O4/MgSiO3 submicrospheres reached 242.1 mg 路kg ~ (- 1). The synthesized submicrospheres show their application prospect in the field of heavy metal ion removal. Under mild conditions, three-dimensional layered CdS/ 偽-Fe2O3 Heterojunction nanocomposites were synthesized by simple chemical bath method. CDs / 偽-Fe2O3 has a wide spectral response range under visible light irradiation. We applied it to the experiment of photocatalytic reduction of Cr (VI). The effects of the molar ratio of CdS to 偽-Fe2O3 on the crystal form, microstructure, optical absorption properties and photocatalytic reduction of Cr (VI) were studied. The results show that when the content of CdS is moderate (the molar ratio of Fe atom to Cd atom is 1.25 鈮，

本文編號：2484284