Photocatalytic CO₂ fixation is widely considered as a promising approach for recycling carbon-based energy resources. However, it is still beyond practical application due to the low efficiency and poor selectivity. Therefore, a TiO₂–MoS_xSe_y heterostructured nanotree has been designed for product-oriented optimization of photocarrier transport during the photocatalytic CO₂ fixation. The controllable S/Se ratio in MoS_xSe_y can tweak the band edge, that is, the active energy level for CO₂ fixation, achieving a tunable C₁ and C₂ production. TiO₂ and MoS_xSe_y synergizes under a dual-excitation mechanism to favor the separation and transports of the photocarriers. Prominently, a CH₃CH₂OH generation rate of 704.38 μmol g^–1 h^–1 has been archived with S/Se < 1, while another C₁ product of HCOOH and a C₂ product of CH₃COOH can be gradually obtained with S/Se > 1.

中文翻译：

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通过可控的S / Se比在TiO ₂ -MoS _x Se _y双激发异质结构纳米树中连续选择性光催化CO ₂固定

光催化固定CO ₂被广泛认为是回收基于碳的能源的有前途的方法。然而，由于效率低和选择性差，它仍然超出了实际应用。因此，已经设计了TiO ₂ -MoS _x Se _y异质结构纳米树，用于在光催化CO ₂固定过程中优化载流子传输的产品导向。MoS _x Se _y中可控的S / Se比可以调整带边缘，即用于CO ₂固定的有效能级，从而实现可调节的C ₁和C ₂产量。TiO ₂和MoS_x Se _y在双重激励机制下协同作用，有利于光载体的分离和传输。突出地，当S / Se <1时，归档的CH ₃ CH ₂ OH生成速率为704.38μmolg ^–1 h ^–1，而通过以下方法可以逐渐获得HCOOH的另一C ₁产物和CH ₃ COOH的C ₂产物。S / Se> 1。