Abd-Rabboh Hisham S M, Galal A H, Aziz Rafi Abdel, Ahmed M A
Chemistry Department, Faculty of Science, King Khalid University PO Box 9004 Abha 61413 Saudi Arabia.
Department of Chemistry, Faculty of Science, Ain Shams University Abbassia Cairo 11566 Egypt
RSC Adv. 2021 Sep 2;11(47):29507-29518. doi: 10.1039/d1ra04717e. eCollection 2021 Sep 1.
The destruction of toxic pollutants and production of hydrogen gas on the surface of semiconductors under light irradiation is the main significance of photocatalysis. Heterojunctions with matching in band gap energy are urgently required for enhancing the redox power of the charge carriers. A step S-scheme BiVO/SnO nano-heterojunction was carefully synthesized for a successful photodegradation of amaranth dye and photocatalytic hydrogen evolution. Tetragonal SnO nanoparticles of 80 m g surface area and distinct mesoporous structure were fabricated by a sol-gel route in the presence of Tween-80 as the pore structure directing agent. BiVO nanoparticles were deposited homogeneously on the SnO surface in an ultrasonic bath of power intensity 300 W. The photocatalytic efficiency in the destruction of amaranth dye soar with increasing BiVO contents of up to 10 wt%. The hydrogen evolution rate reached 8.2 mmol g h, which is eight times stronger than that of pristine SnO. The sonicated nanocomposites were investigated by XRD, BET, FESEM, HRTEM, EDS, DRS and PL techniques. The step S-scheme heterojunction with superior oxidative and reductive power is the primary key for the exceptional photocatalytic process. The PL of terephthalic acid and the scavenger trapping experiments reveal the charge migration through the step S-scheme mechanism rather than the type (II) heterojunction mechanism.
光照射下半导体表面有毒污染物的分解和氢气的产生是光催化的主要意义所在。为提高电荷载流子的氧化还原能力，迫切需要带隙能量匹配的异质结。通过精心合成了一种阶梯型S型BiVO₄/SnO₂纳米异质结，成功实现了苋菜红染料光降解和光催化析氢。以吐温-80作为孔结构导向剂，采用溶胶-凝胶法制备了比表面积为80 m²/g且具有独特介孔结构的四方相SnO₂纳米颗粒。在功率强度为300 W的超声浴中，BiVO₄纳米颗粒均匀沉积在SnO₂表面。随着BiVO₄含量增加至10 wt%，苋菜红染料的光催化降解效率大幅提高。析氢速率达到8.2 mmol g⁻¹ h⁻¹，比原始SnO₂高八倍。采用XRD、BET、FESEM、HRTEM、EDS、DRS和PL技术对超声处理后的纳米复合材料进行了研究。具有优异氧化还原能力的阶梯型S型异质结是卓越光催化过程的关键所在。对苯二甲酸的PL和清除剂捕获实验表明，电荷迁移是通过阶梯型S型机制而非II型异质结机制。
