Design and construction of Z-scheme photocatalyst has been attracted much attention, which is a great challenge to develop highly efficient photocatalyst without the external redox mediators. Herein, a novel efficient redox-mediator-free Z-scheme BiPO₄/BiOCl_0.9I_0.1 heterojunction is synthesized in situ via a mild 90 °C water bath reaction. The as-synthesized BiPO₄/BiOCl_0.9I_0.1 heterostructure exhibits outstanding photocatalytic performance for degradation of phenol and Rhodamine B, approximately 2.6 and 4.3 times higher than that of BiOCl_0.9I_0.1, respectively. The BiPO₄/BiOCl_0.9I_0.1 heterostructure have multiple vacancies and valence, such as Bi⁵⁺, Bi³⁺, Bi^(3−x)+, I⁻, I₃⁻, and IO₃⁻, which could facilitate the charge separation and transfer in the photocatalytic process. The higher photocatalytic activity of redox-mediator-free Z-scheme BiPO₄/BiOCl_0.9I_0.1 heterostructure could be attributed to the strong redox ability, multiple charge transfer channels via the various defects, and tight contact due to in situ synthesis. The finding provides some new insights for the design of effective direct Z-scheme photocatalyst with multiple defects.

Z型光催化剂的设计和构建已引起广泛关注，这是开发没有外部氧化还原介质的高效光催化剂所面临的巨大挑战。本文中，经由温和的90℃水浴反应原位合成了新颖的有效的无氧化还原介质的Z-方案BiPO ₄ / BiOCl _0.9 I _0.1异质结。合成后的BiPO ₄ / BiOCl _0.9 I _0.1异质结构对苯酚和若丹明B的降解表现出出色的光催化性能，分别比BiOCl _0.9 I _0.1高2.6倍和4.3倍。BiPO ₄ / BiOCl _0.9 I_0.1异质结构有多个空位和化合价，例如Bi ⁵⁺，铋³⁺，铋^（3-X）+，我^- ，我₃ ^- ，和IO ₃ ^- ，这可能有利于在光催化过程中的电荷分离和传输。不含氧化还原介体的Z方案BiPO ₄ / BiOCl _0.9 I _0.1异质结构的较高光催化活性可归因于较强的氧化还原能力，通过各种缺陷的多个电荷转移通道以及由于原位合成而产生的紧密接触。这一发现为设计具有多种缺陷的有效的直接Z方案光催化剂提供了一些新的见识。