The interaction between heavy particles with high Stokes number ($St$) and the wall, known as the particle–wall (P–W) process, widely exists in natural and engineering two-phase flows, whereas its effects on particle-laden flows and the large-scale/very large-scale turbulent motions (VLSM) remain unclear. In this paper, two types of wind-blown sand-laden flows were experimentally designed and investigated by keeping the same free stream velocity, flow Reynolds number and particle $St$ number. In the first type, sand particles were directly blown from a sand bed at the bottom wall of the wind tunnel, and the P–W process occurred in the whole wall-normal region of the sand-laden flow. In the second type, sand particles were released from a feeder at the top wall of wind tunnel, and the P–W process was only present in a lower wall-normal region. Simultaneous two-phase particle image/tracking velocimetry measurements were conducted for uncovering the characteristics of turbulent structures in the particle-laden turbulent boundary layers. The results confirmed that the VLSM with streamwise scales exceeding $3\delta$ ($\delta$ is boundary layer thickness) above a certain height exist in both types of the sand-laden flows and could be significantly affected by the P–W process. That is, in the region without the P–W process, the presence of sand particles can enlarge the VLSM, while in the region with the P–W process, the VLSM are substantially reduced in size or even destroyed. The reduction degree is found to be closely related to the strength of the P–W process.